NIST GCR 16-003
 

Validation for Downstream 

Computer Aided Manufacturing 

and Coordinate Metrology 

Processes 

Asa Trainer 

International TechneGroup Incorporated 

This publication is available free of charge from: 

http://dx.doi.org/10.6028/NIST.GCR.16-003 
 

 

 

 

 

 

NIST GCR 16-003 

Validation for Downstream 

Computer Aided Manufacturing 

and Coordinate Metrology 

Processes 

Prepared for 

Allison Barnard Feeney 

Thomas Hedberg, Jr. 

U.S. Department of Commerce 

Engineering Laboratory 

National Institute of Standards and Technology 

Gaithersburg, MD 20899-8260 

By 

Asa Trainer 

International TechneGroup Incorporated 

This publication is available free of charge from: 

http://dx.doi.org/10.6028/NIST.GCR.16-003 

September 2015 

U.S. Department of Commerce 

Penny Pritzker, Secretary 

National Institute of Standards and Technology 

Willie May, Under Secretary of Commerce for Standards and Technology and Director 
 

 

 

 

 

 

 

 

 

 

 

DISCLAIMERS 

This report was prepared for the Engineering Laboratory of the National Institute of 

Standards and Technology (NIST) under the following cooperative agreement: 

•	 70NANB14H256, International TechneGroup Incorporated, “Validation for 

Downstream Computer-Aided Manufacturing and Coordinate-Metrology 

Processes” 

Any opinions, findings, conclusions, or recommendations expressed in this publication do 

not necessarily reflect the views of NIST. Additionally, neither NIST nor any of its 

employees make any warranty, expressed or implied, nor assume any legal liability or 

responsibility for the accuracy, completeness, or usefulness of any information, product, 

or process included in this publication. 

This paper may identify certain commercial systems. Such identification does not imply 

recommendation or endorsement by NIST. Nor does it imply that the products identified 

are necessarily the best available for the purpose. 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

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Validation for Downstream Computer-Aided 

Manufacturing and Coordinate-Metrology Processes
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Semi-Annual Technical Report 

Reporting Period - April 1, 2015 to September 30, 2015 

ABSTRACT 

To achieve industry’s vision of the Model-Based Enterprise (MBE), the MBE strategy must 

include model-centric data interoperability for design to manufacturing and quality in the supply 

chain. The Model-Based Definition (MBD) is created by the OEM using Computer-Aided Design 

(CAD) tools. This information is then shared with the supplier so that they can manufacture and 

inspect the physical parts. Today, almost all suppliers use Computer-Aided Manufacturing 

(CAM) and Coordinate Measuring Machine (CMM) models respectively for these tasks. In the 

MBE vision for model-centric data exchange, the CAD model must include product and 

manufacturing information (PMI) in addition to the shape geometry. Today’s CAD tools can 

generate models with embedded PMI, with the emergence of STEP AP242, a standards-based 

model with embedded PMI can now be shared downstream. This project investigates the ability 

to utilize a STEP AP242 model with embedded PMI for CAD-to-CMM data exchange. The 

project examines transformational processes and identifies gaps that will impact industry’s 

ability to achieve model-centric data interoperability cost-effectively in the pursuit of the MBE 

vision. 

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TABLE OF CONTENTS 

EXECUTIVE SUMMARY.............................................................................................................. 3
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PROJECT TEAM.......................................................................................................................... 4
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INTRODUCTION.......................................................................................................................... 5
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MOTIVATION FOR THE STUDY ................................................................................................. 7
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METHOD...................................................................................................................................... 8
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Approach Outline ...................................................................................................................... 8
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Determination of Test Cases - Models and Data Sets.............................................................. 9
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Definition of Validation Metrics ................................................................................................. 9
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Development of CAM/CM (ACIS) Validation Algorithm .......................................................... 10
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Validation of Extended ACIS and Collection and Analysis of Validation Metrics.................... 10
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Scope and Mapping Process for PMI Mapping to QIF ........................................................... 11
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RESULTS................................................................................................................................... 11
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Results from Mapping PMI between STEP and QIF .............................................................. 11
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Results from Validation of Original Project Test Models......................................................... 12
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Results from Validation of Test Models from NIST Data Sets ................................................ 14
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DISCUSSION AND CONCLUSIONS ......................................................................................... 16
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STEP - QIF PMI Mappings ..................................................................................................... 16
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Validation of Extended ACIS .................................................................................................. 17
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Conclusions ............................................................................................................................ 25
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ACKNOWLEDGEMENTS........................................................................................................... 26
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REFERENCES........................................................................................................................... 28
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APPENDICES ............................................................................................................................ 29
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Appendix A: Mapping PMI into STEP and QIF ....................................................................... 29
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Appendix A.1: Mapping GD&T into STEP and QIF............................................................. 29
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Appendix A.2: Mapping Linkages into STEP and QIF ........................................................ 38
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Appendix A.3: Mapping PMI Features and User Defined Tolerances into STEP and QIF . 39
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............................................................................................................................................ 41
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Appendix A.4: Mapping of Boundary Representation (BREP) Geometry into STEP and QIF
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Appendix A.5: Mapping Other MBD-related Items into STEP and QIF............................... 42
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Appendix B: Validation Results for Test Models..................................................................... 43
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Appendix B.1: Validation Differences by PMI Category for Test Models ............................ 43
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Appendix B.2: Percent Clean (%) by PMI Category for Test Models.................................. 44
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EXECUTIVE SUMMARY 

To achieve industry’s vision of the Model-Based Enterprise (MBE), the MBE strategy must 

include model-centric data interoperability for design to manufacturing and quality in the supply 

chain. The Model-Based Definition (MBD) is created by the OEM using Computer-Aided Design 

(CAD) tools. This information is then shared with the supplier so that they can manufacture and 

inspect the physical parts. Today, almost all suppliers use Computer-Aided Manufacturing 

(CAM) and Coordinate Measuring Machine (CMM) models respectively for these tasks. Until 

recently data for shape has been transferred downstream via STEP AP203 but collaborators 

had to handle product manufacturing information (PMI, i.e. dimensions and tolerances) for 

metrology planning and execution via transcription from drawings. With the recent availability 

of STEP AP242, the promise of direct transformation of design data to downstream consumers 

including PMI in a single MBD package now exists. The vision of MBE is that by using STEP 

AP242 for interoperability of rich design information with the manufacturing and metrology 

supply chain, the process would be faster, more accurate, and be less error prone. 

This project was developed to investigate the interaction between STEP AP242 and CAM and 

CMM systems by using ACIS, the predominant modeling kernel in the manufacturing and 

metrology space. Algorithms were developed to transform the data but more importantly to 

show that validation was a critical component of success in the transformation process. In 

addition to examining ACIS as a vehicle for transforming design data into metrology data, the 

team also examined the emerging QIF standard and mapped it to STEP AP242 to determine 

what effort might be required to make STEP and QIF the standards of choice for this process. 

The project team included interoperability experts in STEP and ACIS as well as QIF. The team 

developed metrics for validation of PMI data into ACIS and examined the results of the STEP to 

ACIS transformation and validation process. The team also examined STEP and QIF standards 

to determine where there was commonality, where there was overlap, and where there were 

gaps between the standards. 

This project demonstrated the ability to transform design model data that included PMI from 

STEP AP242 data into extended ACIS for use by Manufacturing and Metrology systems. It 

confirmed that transformation of such semantically rich PMI data requires an automated method 

to validate that the transformed data is complete and correct for downstream use. 

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PROJECT TEAM 

Project Coordination 

Asa Trainer, International TechneGroup Incorporated 

PMI Mapping 

Curtis Brown, Honeywell FMT 

Victor Mikushin, Capvidia 

Ed Paff, International TechneGroup Incorporated 

Tom Kramer, NIST 

Tomasz Luniewski, Capvidia 

Daniel Campbell, Metrosage 

Hui-Min Huang, NIST 

Validation Algorithm Development 

Ed Paff, International TechneGroup Incorporated 

Dave Smith, International TechneGroup Incorporated 

Validation Analysis 

Doug Cheney, International TechneGroup Incorporated 

Research Advisors 

Allison Barnard Feeney, National Institute of Standards and Technology 

Thomas Hedberg, Jr., National Institute of Standards and Technology 

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INTRODUCTION 

The challenge: Given industry’s vision of MBE, and immerging research into modelcentric data interoperability between design and manufacturing and quality 

inspection, shouldn’t these new model-centric data interoperability processes include 

validation mechanisms to ensure data quality and provide a metric for measuring the 

evolution of these processes as they mature? 

To achieve the industry vision of the Model-Based Enterprise (MBE), the MBE strategy must 

include model-centric data interoperability for design to manufacturing and quality in the supply 

chain. The Model-Based Definition (MBD) is created by an OEM using Computer-Aided Design 

(CAD) tools. This information is then shared with the supplier so that they can manufacture and 

inspect the physical parts. Much of the supply base consists of Small and Medium Enterprise 

(SME) manufacturers. Today, almost all suppliers use Computer-Aided Manufacturing (CAM) 

and Coordinate Measuring Machine (CMM) models respectively for these tasks. Traditionally, 

design data is provided from the OEM to supplier in the form of full detail 2-dimensional (2D) 

drawings. More recently the data has also included a 3-dimensional (3D) model with shape 

geometry. This model is often provided in a standards-based model format – STEP AP203 is 

prevalent. However, in addition to geometry, the downstream CAM and CMM processes also 

require product and manufacturing information (PMI) in order to fabricate and inspect the 

physical part. 

The vision of MBE and supply chain interoperability using an MBD-based process has great 

potential to improve efficiency and achieve higher product quality. In 2014 a new STEP 

Application Protocol (AP), AP242, was published which was developed to consolidate and 

replace previous APs and includes support for PMI (Reference A). STEP AP242 would seem 

to represent the way forward to solving this downstream interoperability problem. 

As stated in Reference A, many downstream systems have proprietary direct translation 

capability and that some of those capabilities include PMI support, though none of these 

systems yet support the STEP standard. The long term desire, however, is for the CAM and CM 

communities to support the direct consumption of STEP AP242 and other international 

standards with precise geometry and semantic PMI data, a more achievable approach in the 

short term is to leverage the modeling kernels that are the basis for many CAM and CM 

systems, the ACIS and Parasolid kernels. The research conducted in Reference A clearly 

demonstrates that this standards-based approach to downstream interoperability is feasible. 

While standards-based exchange provides significant benefit to industry, one challenge that 

must be addressed is verification and validation of translations, ensuring adequate product data 

quality. The ability to validate that model data is transformed properly during the 

interoperability process is important to manufacturers large and small. Without it, data 

consumers cannot be sure that their content is complete and accurate and the risk of potentially 

costly rework is a major concern. Performing such validation by hands-on inspection has been, 

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when 2D drawings are the method for exchange of manufacturing data in the supply chain, the 

purview of design checkers. The need for confidence in the conformance of 3D model data to 

quality standards is well understood [13]. While validation of 3D modeling data by hands-on 

inspection is certainly possible, it is not desirable. The process is painstakingly slow, requires a 

high level of skill and attention to detail, and there is a high likelihood of error even when done 

by a skilled practitioner. It is also important to note that even though the burden of validation is 

important for geometry interoperability, it is even more critical and more challenging when PMI 

interoperability is required. As such, formal requirements for verification of model data, 

particularly PMI data, and validation of derivative variants of that data for collaboration purposes 

are now in place [14]. 

Automation of validation for CAD-to-CAD interoperability processes is becoming an important 

tool particularly for 3D model data containing PMI (Reference B and Reference C). Validation 

of transformed model data in the CAM and CM context is just as important to instilling 

confidence in automated processes for the CAM and CM communities. 

STEP is generally considered to be the method of choice for CAD-to-CAD interoperability for 

shape, and with the availability of semantic PMI constructs in STEP AP242, STEP shows 

promise as a strong candidate for interoperability between CAD and CM. The metrology 

community has developed their own standard, the Quality Information Framework (QIF, 

Reference D), to support the unique needs of that community. QIF contains data structures for 

collecting, organizing, and analyzing measurement data and metrology systems are beginning 

to make use of those QIF standard structures. QIF also has its own MBD data structures for 

both shape (geometry) and PMI. A case could be made for interoperability between these two 

complementary standards. 

First hypothesis: Transformation of MBD data from CAD to CAM and CAD to CMM 

requires a mechanism to validate the integrity and quality of the downstream data 

and that validation of such data provides insight into the state of art for downstream 

interoperability systems. 

Second hypothesis: The STEP AP242 and QIF standards share common ground 

as far as geometry and PMI interoperability is concerned and that there is an 

opportunity to bridge the gap between CAD and CMM communities through 

interoperability between these two standards. 

This project will test these two hypotheses. The first hypothesis is that model-based data 

transformed from CAD-to-CAM and CAD-to-CMM via STEP AP242 and ACIS can be validated 

using automated methods and that there is significant value in performing such validations to 

evaluate the nascent capabilities for interoperability between design and downstream 

processes. The second hypothesis is that STEP AP242 and QIF 2.0 are aligned as far as 

geometric and PMI data are concerned and that harmonization these standards represent a 

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potential way forward for future interoperability tools and processes. The project will answer the 

question of the current state of evolution of early CAD-to-CMM transformation tools through 

demonstration and measured results. It will also answer the question of how closely aligned the 

two standards are that may connect CAD to CMM. It will provide for discussion and 

recommendations based upon the findings and observations. Finally, the project will draw 

conclusions about the level of maturity of standards-based model-centric data interoperability 

between upstream creation and downstream consumption. 

MOTIVATION FOR THE STUDY 

The motivation: Demonstrate the value of validation of model-centric CAD-to-CAM 

and CAD-to-CMM data interoperability when using STEP AP242 with embedded 

PMI transformed into extended ACIS data. 

The research team believes this project will assist industry in its drive to achieve the vision of 

the Model-Based Enterprise down into the manufacturing supply chain if the above hypotheses 

can be substantiated. 

A standards-based workflow for design to manufacturing and inspection involves exchange of 

CAD-to-AP242-to-CAM-and-CMM models. Validation and verification of this translation process 

is important, especially for regulated industries. An important part of quality assurance is 

traceability back to the design definition. To assure compliance at any point in the 

manufacturing or inspection process, it is essential to have validation and verification of the 

models throughout the data-exchange process. 

When moving to a model-based paradigm, the verification process is more complex since the 

goal is for the model geometry and PMI to be consumed directly by downstream software 

systems. Verification in this context requires each and every PMI element be analyzed for 

syntactical and semantic accuracy including proper association of the PMI to geometric 

references in the 3D geometry. 

In addition to verifying that PMI content has been authored correctly, each time the data is 

transformed – from CAD to STEP and from STEP to CAM/CMM – the data must be validated to 

be sure no data corruption occurred during the transformation process. Since the information 

content in the 3D model is no longer in the form of a visually inspect-able 2D drawing, special 

software algorithms are required to perform the verification and validation processes on all but 

the simplest models. 

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Figure 1 - Verification and validation process flow diagram 

In the case of this project, we performed verification and validation following the process 

outlined in Figure 1. We performed verification and validation using a combination of traditional 

visual inspection techniques and automated techniques. In general use on more complex 

models, automated techniques would have been required. 

The research team also believes that the developed technology and the aforementioned 

standards are extensible to include PMI data items beyond those used in the test models. The 

application can successfully exchange more complex parts than the project’s demonstrated test 

models. The software application used in this demonstration will achieve Technology 

Readiness Level (TRL) 6. A list of TRL definitions is given in Appendix C. This provides 

motivation for commercialization of interoperability validation tools to provide standards-based 

3D models with embedded PMI to the CAM and CMM industry. It is expected that CAM and 

CMM tools providers would be motivated to commercialize the ability to receive and utilize 

standards-based models with embedded PMI. 

As the identified gaps in current tools and standards are addressed to achieve this level of 

commercialization, and the process and skill gaps are overcome by industry users, the 

opportunity to improve efficiency and effectiveness across the product lifecycle will be provided 

in design, manufacturing, inspection, and collaboration across the supply chain. 

METHOD 

The methodology used to test the above hypotheses is described below. 

Approach Outline 

To test the hypotheses, the following approach was used: 

•	 Determine test cases for validation processing, 

•	 Develop metrics for evaluating validation results, 

•	 Develop prototype software for automatic validation of extended-ACIS models against 

original CAD data, 

•	 Validate extended-ACIS models against source STEP model data, 

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•	 Collect and analyze metrics data to evaluate the maturity of STEP to ACIS 

transformation process and also to evaluate the maturity of the validation process itself, 

•	 Determine the scope for mapping of STEP to QIF, and 

•	 Map model-based PMI requirements from STEP to QIF and identify gaps that inhibit 

development of interfaces between these two standards. 

Each of these elements of the approach is discussed below. 

Determination of Test Cases - Models and Data Sets 

In keeping with the collaborative nature of this project and its companion project (Reference A), 

the initial two test cases for this project were selected to be the same two models selected by 

that companion project team. This was a logical choice as native NXTM CAD model data 

already existed and had been used as the source for the intermediate STEP models and the 

ACIS models in CAM and CM. Furthermore, all of the data - native, STEP, and ACIS - had 

been thoroughly analyzed by hand for completeness and correctness. These data were used to 

exercise the developed algorithms for automatically validating PMI-extended ACIS against 

native CAD models. These test cases are shown in Figures 2 and 3 below. 

Figure 2 - Test Case #1 – Milled Part 827-9999-904 

Figure 3 - Test Case #2 – Revolved Part 827-9999-903 

The above two test cases were augmented by leveraging a subset of the now well-known NIST 

test cases and models available from References B and C. The test data were chosen from 

STEP files generated during several recent PDES/ProSTEP CAx test rounds. The selected 

STEP models were those for which semantic PMI annotation had been generated. 

Definition of Validation Metrics 

A mechanism was needed to quantify the extent of successful transformation of PMI annotation 

information from the original CAD PMI data to that same PMI data in ACIS format. The authors 

selected five major categories of PMI annotation data to be used as metrics for this initial 

validation research activity. For each of these major categories, a selected set of semantic PMI 

content (parameter values) would be evaluated. 

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The PMI annotation categories selected and the semantic parameters to be used for validating 

for each annotation type are shown Table 1 below: 

Table 1 - PMI Annotation Categories for Validation Purposes 

PMI Category PMI Content Validated 

Datum Feature Symbol (DFS) Identifier 

Datum Target Symbol (DTS) Identifier 

Target type 

Dimension (DIM) Tolerance format 

Nominal value (with unit) 

Upper and lower values (with unit) 

Feature Control Frame (FCF) Type 

Symbol 

Overall tolerance 

Datum reference frame identifiers 

Modifiers 

Note (NOTE) Text 

- Symbols shown in parentheses above are used in the validation results table in 

Appendix B to identify each PMI annotation category listed 

Development of CAM/CM (ACIS) Validation Algorithm 

The plan for algorithm development was split into two phases. The first phase was to focus on 

the development of a prototypical capability to validate ACIS geometry. Data structures for 

geometry in ACIS are well known, stable, and other geometry data models can easily be 

mapped to ACIS. Following the development of a validation capability for geometry, the 

second, more challenging phase would focus on development of validation capability for PMI 

data. This second phase was expected to be more complex. This was due to the fact that 

ACIS is first and foremost a geometry model schema and that extensions to include PMI 

constructs are evolving. Further comments on this extended ACIS, its maturity for PMI, and the 

effects of that maturity on validation will be discussed in the results section. 

Validation of Extended ACIS and Collection and Analysis of Validation 

Metrics 

Validation of extended ACIS was performed by applying the developed algorithm to evaluate 

geometry and PMI entities in both each STEP model and its derived ACIS model. This was 

done for the original companion project test cases as well as selected members of the broader 

NIST test suite. For each test case, each entity pair was analyzed for correctness of the 

mapping and compared for matching values of the entity’s properties. The metrics described in 

Table 1 were counted as either “clean” or “different” for every PMI entity pair. An entity pair was 

considered “clean” if the entity structure properties were preserved during transformation and if 

the values of those properties in the target ACIS data matched the values of the properties in 

the source STEP data. The results were analyzed to determine, where possible, whether any 

differences were a result of issues in the transformation algorithm or a result of the validation 

algorithm. 

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Scope and Mapping Process for PMI Mapping to QIF 

For the STEP QIF mapping exercise, a group of STEP and QIF subject matter experts from ITI, 

Honeywell FM&T, Capvidia, and Metrosage, together with STEP and QIF standards experts 

from NIST, gathered in a workshop at the Spring 2015 PDES Offsite in Gaithersburg, MD, to 

form a working group responsible for the PMI mapping task. That working group collectively 

determined ground rules for the mapping research and outlined a reasonable scope for the 

mapping process. The working group agreed to leverage the STEP and ACIS mapping tables 

produced as part of the companion project (again Reference A) as the framework for the QIF 

mapping. The working group also agreed to focus attention on the subset of QIF referred to as 

QIF MBD – that part of the QIF standard addressing product shape and PMI content that would 

likely be received from upstream design-related processes. 

Following the workshop, the working group held bi-weekly conference calls over the course of a 

3-month period to review mapping progress, discuss issues concerning interpretation of the 

standards, and formulate new work items for the next two-week period. Over the course of that 

period the existing STEP-ACIS mapping table was extended to include QIF MBD constructs. 

Additionally, gaps between the standards that could not be closed were identified for later 

resolution. 

RESULTS 

Results from Mapping PMI between STEP and QIF 

A broad subset of the possible categories of PMI data were mapped as part of this project. The 

mapping categories [STEP -> QIF] are listed below: 

•	% Boundary representation geometry, 

•	% Construction geometry, including points, planes, coordinate systems, curves, surfaces, 

and axes, 

•	% GTOLs and dimensions (including their tolerances), 

•	% Default or general tolerances, 

•	% Notes (including general and flag notes), 

•	% Tables, 

•	% Title block information, 

•	% Datums, including datum targets, datum tags, and datum reference frames, and 

•	% Saved views. 

Certain categories of data were not mapped [STEP to QIF] as part of this project. Mapping of 

the three non-mapped data categories is a subject for future research. These categories are 

indicated in the list below: 

•	% Layers and groups, 

•	% Assembly structure, including component instancing, and 

•	% Cross-sections (and planar sketches). 

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The result of the mapping exercise was a table of PMI elements and their appropriate entities in 

STEP, ACIS, and QIF formats. For the purposes of discussion in this report, the table was 

broken up in to separate sections. Though focused on mapping of PMI related content in this 

study, the authors have included mappings for geometric shape entities for completeness. The 

various mappings are listed below: 

• GD&T Entities 

• Linkage Entities 

• PMI Features and User Defined Tolerances 

• Boundary Representation Geometry Entities 

• Other MBD-related Entities 

All mapping tables are presented in Appendix A and discussed later in this report. An example 

of a portion of the GD&T mapping table is shown in Figure 4 below. 

Figure 4 - Example of PMI(GD&T)/STEP/ACIS/QIF Mapping Table 

Results from Validation of Original Project Test Models 

Development and demonstration of a process to exchange standards-based models with 

embedded PMI from design to downstream systems was successful within the scope of the 

limited test models used in this project. The validation results, as defined by PMI element 

counts, for the downstream models are provided in Table 2. The validation shows that all 

dimensions, tolerances, and datum features were transformed and exchanged. 

Indicated in Table 2, general notes could not be mapped to ACIS. Although manual validation 

showed correct PMI counts (for PMI other than general notes), further detailed examination by 

automated validation of the downstream models using analysis software found anomalies in the 

transformed data. 

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Table 2: Validation of model transformations using embedded PMI entity count 

PMI Elements NX STEP ACIS Mastercam MiCAT 

(by format) 

Model (827-9999) -903 -904 -903 -904 -903 -904 -903 -904 -903 -904 

Dimension 8 54 8 54 8 54 8 54 8 54 

Tolerance 6 13 6 13 6 13 6 13 6 13 

Datum Feature 2 3 2 3 2 3 2 3 2 3 

Notes (not semantic data) 7 8 7 8 0 0 7 8 0 0 

Total 23 78 23 78 16 70 23 78 13 68 

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Table 3 shows the results of automated validation of model transformations. In the -904 model, 

the automated validation tool showed that though all dimensions were transformed and, for the 

most part, semantically correct, a rule violation occurred when the dimension tolerance zone for 

one dimension was considered large relative to its nominal value. The -903 model, like the -904 

model, was flagged for an instance of this same rule violation. The -903 model was also flagged 

for failure to maintain the semantic definition of limit dimensions in four instances of that 

dimension type when transformed from STEP to ACIS. 

Table 3: Validation of models using analysis software 

Model File	 DFS1 DIM2 FCF3 Clean
 

Clean Clean Clean Percent
 

827-9999-903 2 3 6 69% 

827-9999-904 3 53 13 99% 

The counts shown in Table 3 refer to the number of entities that are clean (e.g., pass all syntax 

and semantic validity checks during analysis of STEP to ACIS transformations). The clean 

percent in Table 3 ignores note entity errors. 

1 DFS = Datum Feature Symbol 2 DIM = Dimension 

3 FCF = Feature Control Frame 

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Example validation results are shown in Figure 5 (for semantic representation PMI) below.
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Figure 5 - Example of Validation of extended-ACIS PMI with Source STEP Model 

Note that, in the example shown, though the value of the dimension was preserved during 

transformation, the units of the dimension value were lost. Investigation of this observed 

behavior suggests that adjustment to ACIS handling of units is required. 

Results from Validation of Test Models from NIST Data Sets 

A broader suite of models (the NIST CTCs and FTCs from Reference C and/or D were also 

processed to identify what additional coverage gaps might exist. Validation of the STEP data 

relative to the original master CAD models was published in the above references and will not 

be repeated here. Instead, the validation results described in this report are for the validation of 

the extended ACIS models as transformed from the STEP models. It is also important to note 

that the STEP files used in this study are models from the very latest PDES/ProSTEP CAx 

testing rounds. The results are cataloged in Appendix B. 

An example of validation results is shown in Figure 6 (for PMI representation – see “model tree 

panel” lower left [STEP] and lower right [ACIS]). 

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Figure 6 - Example of Successful Validation of extended-ACIS PMI representation with Source STEP Model 

In this NIST CTC01 example, all semantic representation data for a linear dimension of size, 

including association to geometry, was successfully preserved during transformation from STEP 

to extended ACIS. 

In a second example of validation results, shown in Figure 7 (for PMI representation – see 

“model tree panel” lower left [STEP] and lower right [ACIS]), the validation algorithm flags a 

semantic representation change due to the fact that there is no ACIS data structure for the 

nominal value dimension without tolerances found in the source STEP data. The current 

approach to work around this issue is to populate the corresponding ACIS data structure for a 

regular dimension with tolerances and leave the tolerance values set to zero values. 

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Figure 7 - Example of validation of extended-ACIS PMI representation with source STEP Model illustrating an

anomaly 

Additional discussion of validation results, anomalies, and likely causes will be discussed below. 

DISCUSSION AND CONCLUSIONS 

STEP - QIF PMI Mappings 

As discussed earlier in this report, mapping between STEP and QIF resulted in some 

disconnects as shown in Figure 8. Some of these differences are discussed below. 

Figure 8 - Tally of mappings between STEP and QIF 

There was generally good agreement between QIF and STEP for boundary representation 

shape and geometry. Two element types – mesh face and mesh loop - were supported in 

STEP and QIF but were absent in ACIS. 

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The STEP-QIF working group discussed the concept of feature at length but was not able to 

fully close on agreement on a reasonable mapping between the two standards. The concept of 

“feature” is used in many systems and standards but there is often significant variation in the 

meaning and usage of the term among them. STEP has the concept of feature in AP242 

(design feature) as well as AP238 (manufacturing feature), both represent a shape element that 

is flexibly defined by parameters which control the size or location of the shape element. QIF 

also has the concept of feature but that did not have direct STEP equivalent (26 QIF elements). 

It appeared to be a categorized shape aspect. The working group thinks these QIF features 

would map back and forth as shape aspects however they agreed to table the attempt to map 

features and recommend a separate research activity just to explore this construct. 

Another area that should be studied further is that, in QIF, there are a number of user-defined 

tolerance entity types that were included in QIF but not included in STEP or ACIS. The working 

group agreed to table the attempt to map these UDTs and recommend follow-on research to 

explore this construct. 

As shown in Figure 8, a number of ancillary MBD-related elements, also shown in Appendix A.5, 

are important for proper MBD usage and either do not currently have support in one or more 

standards. Examples of this include Notes, which are not supported in ACIS, and both Flag 

Notes and Surface Finish, which are not supported in STEP. In addition, there were two MBDrelated elements that were not supported in any of the examined standards (e.g. Tables and 

Global or General Tolerances). Of the two of these, the ability to capture and map global or 

general tolerances was considered to be a significant impediment to MBD exchange due to its 

widespread use in industry. 

A final observation is that, in many cases, PMI constructs could be mapped for STEP and for 

QIF but not for ACIS. This suggests that STEP to QIF may be a better exchange mechanism 

than STEP to ACIS once downstream consuming systems have developedand begun delivering 

QIF import capabilities. 

Validation of Extended ACIS 

There were a significant number of anomalies in the results for validation of the extended ACIS 

when performed by rigorous automated means. As mentioned above, note entities were one 

category of PMI that was not transferred to ACIS in all test cases. This was due to the lack of 

an appropriate data structure to hold them in ACIS. 

It was also observed that models containing Datum Target Symbols (DTS, CTCs 02 and 05) 

were also not well handled during the data transfer to ACIS regardless of system. Reviewing 

the results in Appendices B1 and B2, the overall percent success of validation, including the 

note and DTS anomalies, was 59%. If the impact of these two issues is ignored, then the 

overall percent success improves to 67%. It is worthwhile to note that in no exchange was the 

DTS type successfully exchanged, i.e. that all semantic structure information was included and 

the values of that semantic data were correct. The reasons for DTS failure were different. 

Three examples that illustrate those different failure modes are shown in Figures 9a, 9b, and 9c 

below for test case CTC02. 

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Figure 9a – Example of validation of extended-ACIS PMI representation with source STEP Model illustrating

complete loss of Datum Target Symbol in the ACIS target model 

Figure 9b – Example of validation of extended-ACIS PMI representation with source STEP Model illustrating 

loss of Associated Geometry for a Datum Target Symbol in the target ACIS model 

As shown in Figure 9a, the PMI data structure for a DTS in this particular source STEP data 

could not be matched to any equivalent data structure in resulting model transformed into ACIS. 

In a second example (Figure 9b), though the PMI data structure in the source STEP data could 

be matched to its equivalent data structure in resulting model transformed into ACIS, the 

association to the geometric surface referenced in the DTS structure was lost. Finally, in Figure 

9c, the PMI data structure in the source STEP data was transferred to the resulting model in 

ACIS however the identifier for the DTS was changed during the exchange process. Issues 

with Datum Target Symbols for test case CTC05 were similar to those found in CTC02. 

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Figure 9c – Example of validation of extended-ACIS PMI representation with source STEP model illustrating 

an identifier change for a Datum Target Symbol in the target ACIS model 

Though non-existent Note capability and widespread Datum Target Symbol failures 

predominated, anomalies did occur in the remaining categories. Referring to Table 4 (below), 

the percentage success for Datum Feature Symbols (DFS), Dimensions (DIM), and Feature 

Control Frames (FCF) were 72%, 64%, and 62% respectively when Notes and DTS failures 

were ignored. 

The results for the CTC01 test case showed the most issues, and variation between systems, in 

dimensions. Datum Feature Symbols and Feature Control Frames were generally stable 

across systems with close correlation between systems. The results for CTC3 and CTC4 test 

case were reasonably good for all vendors, averaging 93% and 84% success, respectively, 

when note failures were ignored. Dimensions were, again, the type with the most issues. 

As stated earlier, the results for the CTC05 test case showed problems for Datum Target 

Symbols (DTS). If DTS errors and note failures are ignored, the results for CTC05 averaged 

62% success. 

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Table 4: Validation of NIST models using analysis software 

Model File DFS4 

Clean 

DIM5 

Clean 

FCF6 

Clean 

Percent7 

Clean 

(xN) 

Percent8 

Clean 

(xNDTS) 

nist_ctc_01_asme1_ct5210_rd_ct242repr.stp 2 7 6 79% 79% 

nist_ctc_01_asme1_ct5210_rd_dk242repr.stp 3 6 6 79% 79% 

nist_ctc_01_asme1_nx800_rd_ct242repr.stp 3 7 6 84% 84% 

nist_ctc_01_asme1_nx800_rd_nx.stp 3 1 6 53% 53% 

nist_ctc_01_asme1_nx800_rd_th.stp 3 9 6 95% 95% 

nist_ctc_02_asme1_ct5210_rc_ct242repr.stp 0 0 0 0% 0% 

nist_ctc_02_asme1_ct5210_rc_dk242repr.stp 0 0 0 0% 0% 

nist_ctc_02_asme1_nx800_rc_ct242repr.stp 0 0 0 0% 0% 

nist_ctc_02_asme1_nx800_rc_nx.stp 6 7 22 80% 100% 

nist_ctc_02_asme1_nx800_rc_th.stp 0 0 0 0% 0% 

nist_ctc_03_asme1_ct5210_rc_ct242repr.stp 6 8 13 93% 93% 

nist_ctc_03_asme1_ct5210_rc_dk242repr.stp 6 8 13 93% 93% 

nist_ctc_03_asme1_nx800_rc_ct242repr.stp 6 8 13 93% 93% 

nist_ctc_03_asme1_nx800_rc_nx.stp 6 8 13 93% 93% 

nist_ctc_03_asme1_nx800_rc_th.stp 6 9 13 97% 97% 

nist_ctc_04_asme1_ct5210_rd_ct242repr.stp 8 7 5 87% 87% 

nist_ctc_04_asme1_ct5210_rd_dk242repr.stp 8 9 3 83% 83% 

nist_ctc_04_asme1_nx800_rd_ct242repr.stp 8 7 4 83% 83% 

nist_ctc_04_asme1_nx800_rd_nx.stp 8 5 5 78% 78% 

nist_ctc_04_asme1_nx800_rd_th.stp 8 7 5 87% 87% 

nist_ctc_05_asme1_ct5210_rd_ct242repr.stp 4 2 6 55% 60% 

nist_ctc_05_asme1_ct5210_rd_dk242repr.stp 4 3 7 64% 70% 

nist_ctc_05_asme1_nx800_rd_ct242repr.stp 2 2 5 45% 50% 

nist_ctc_05_asme1_nx800_rd_nx.stp 2 2 10 70% 78% 

nist_ctc_05_asme1_nx800_rd_th.stp 2 2 6 45% 50% 

Counts: 107 178 186 62% 67% 

Percents: 72% 64% 62% 

Error conditions for Feature Control Frame included loss of geometric associativity, either loss 

or changes to primary datum reference frame identifiers, or loss of FCF type. Several 

examples of these losses are shown in Figures 10a through 10d. 

4 DFS = Datum Feature Symbol 5 DIM = Dimension 

6 FCF = Feature Control Frame 

7 xN = Percent Clean excluding Note entities 

8 xNDTS = Percent Clean excluding Note and Datum Target Symbols 

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Figure 10a - Loss of Feature Control Frame associativity to associated edge geometry 

Figure 10b – Change to Feature Control Frame primary datum reference frame identifier 

Figure 10c – Identifier of Feature Control Frame primary datum reference frame not translated 

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Figure 10d – Loss of Feature Control Frame type 

Dimension-related errors are illustrated in Figures 11a through 11h below. In Figure 11a below, 

the error condition indicates that the values for the nominal and tolerance values have changed. 

A quick calculation shows that the difference is related to improper conversion as the values on 

the left differ to those on right by a factor equal to the conversion factor from degrees to radians. 

It is unclear without further investigation whether the effort occurs in the translation from STEP 

to ACIS or in the validation algorithm display. 

Figure 11a - Angular bilateral dimension nominal and tolerance values changed 

Figure 11b illustrates a problem with extended ACIS in that there is no separate data structure 

for limit dimensions. To provide a workaround, dimensions of this type were recast as nominal 

dimensions with upper and lower tolerances when converted from STEP to ACIS. The 

validation algorithm needs to be adjusted to understand this workaround. Figure 11c shows the 

loss of units on tolerance values. Representation of the proper units in the ACIS data is critical 

to reuse in the Metrology planning system. The use of not-to-scale dimensions, in Figure 11d, 

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Figure 11b - Limit dimension nominal value added and set to zero 

Figure 11c – Units on linear bilateral dimension nominal and tolerance values lost 

Figure 11d - Not to scale dimension nominal and tolerance values uncertain 

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shows a particularly challenging problem for automated systems which will need to account for 

such uses in 3D data. This connection between a native dimension’s to-scale value and its notto-scale value were likely lost during conversion. Further investigation is required. 

In the example of Figure 11e below, a non-toleranced reference dimension has the same issue 

as previously discussed on page 21 for limit dimensions. The validation algorithm needs to be 

adjusted to understand the recasting of non-toleranced and limit dimension workaround. 

Figure 11e - Reference dimension with no tolerances gets tolerances set to zero 

The final three error types will require some more detailed analysis. Each of these has been 

analyzed by the validation algorithm as being “unformated dimensions”. This suggests that 

there were issues when attempting to read the STEP entity and further analysis of the entire 

conversion process is necessary to understand exactly where the anomaly occurred. 

Figure 11f - Unformatted dimension with no nominal value not translated 

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Figure 11g - Unformatted dimension with no tolerances gets tolerances set to zero 

Figure 11h - Unformatted dimension with no tolerances not translated 

Though some issues with PMI mapping into extended ACIS have been resolved and coverage 

for many typical PMI constructs are supported, other PMI mappings into extended ACIS remain 

unresolved due to problems in ACIS. Those unresolved ACIS issues will likely remain open 

issues for consideration as further research in a future project. 

Conclusions 

This project sought to provide initial research necessary to understand the unique nature of 

CAM and CM community’s needs in the area of interoperability between upstream design 

systems and those CAM and CM systems and how their needs map to existing standards, the 

development of algorithms to perform these validations of CAM and CM models, and testing 

these validation processes on a representative set of example CAD models that have been read 

by CAM and CM systems, validating these CAM and CM data models against their STEP 

source models for data loss during transformation. 

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ACIS is a typical modeling kernel in the CAM and CM space and would seem to be a good 

target for a transformation and validation process for passing design data downstream to these 

systems. The research hypothesized here suggested that using a STEP AP242 to extended 

ACIS translation process and following that translation with an ACIS to STEP validation would 

be good first step toward the promise of true MBD, i.e. the ability to share design data including 

PMI with downstream consumers in the manufacturing and metrology spaces. The results of 

this research show that there is a clear requirement for validation, as transformation of semantic 

data structures needed for machine consumption downstream require in-depth automated 

validation processes to ensure data integrity, to establish confidence in the transformed data, 

and to flag any losses during the transformation process. 

A further conclusion, based on this research is that it is possible to use ACIS as the target for 

conversion of data from STEP AP242. There are, however, gaps in the process and 

recommended practices and algorithm refinements are required to resolve roadblocks and fully 

realize the potential value of MBD data in the CAM and CM domains. The mapping exercise 

performed between STEP AP242, ACIS, and the Metrology community’s Quality Information 

Framework (QIF) standard suggests that transformation between STEP and QIF might be a 

strong contender as the mechanism of choice for exchange between design and metrology. 

The mappings identify data model elements, properties, and relationships which are unique to 

each standard and those which are equivalent between them. QIF has unique capabilities, not 

shared with STEP AP242, but which are necessary to properly communicate metrology data 

and process. 

This study benefits end users, software developers, and standards experts by helping all of 

these groups better understand the relative strengths and weaknesses of each standard. It will 

also assist developers to improve translation and validation applications between the standards. 

And it will provide strategic direction for the standards experts as they seek to refine and further 

harmonize the standards, improving interoperability between the design domain and the 

manufacturing and metrology domains over time. 

ACKNOWLEDGEMENTS 

The team would first like to recognize the NIST System Integration Division, Engineering 

Laboratory, for providing this project opportunity. The Digital Thread is an important concept for 

industry. NIST focus and investment in product lifecycle capabilities and standards is truly 

recognized. Especially, we thank Allison Barnard Feeney and Tom Hedberg who have provided 

the leadership in establishing the Digital Thread for Smart Manufacturing. The project team fully 

supports the drive to investigate the product lifecycle holistically and extend the digital thread of 

information with easy implementation into manufacturing systems. NIST has provided a 

significant seed opportunity for commercialization of standards-based model-centric data 

interoperability – enabling industry’s vision of the Model-Based Enterprise. 

A project like this would not be possible without the commitment and contributions from a 

number people. The project team would like to acknowledge the following companies and 

individuals who participated in various elements of the grant. 

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Honeywell FMT, Kansas City, MO, provided consulting services for the STEP- QIF mapping 

activity. Curtis Brown of Honeywell FMT contributed to an understanding of the current and 

expected near-term states of the QIF standard. Curtis also contributed significantly to 

development of the STEP – QIF mapping. 

Capvidia, Leuven, Belgium, provided consulting services for the STEP- QIF mapping activity. 

Tomazs Luniewski and Victor Mikushin of Capvida contributed to an understanding of the 

structure of the QIF standard and how the QIF standard is implemented in practice. Victor also 

contributed significantly to development of the STEP – QIF mapping. 

Daniel Campbell, of Metrosage and Tom Kramer and Hui-Min Huang of NIST provided valuable 

editorial contribution to the STEP- QIF mapping activity. 

International TechneGroup Incorporated, Milford, OH, provided overall program execution, grant 

administration, and project management as well as technical development of validation 

components and validation analysis of model data. Ed Paff was responsible for translation 

component development as well as providing insights into the current and expected near-term 

states of the ISO10303 STEP standard relating to PMI, as well as development of the PMI 

mapping framework and STEP mapping into the framework. Dave Smith was responsible for 

technical development of validation algorithms. Doug Cheney was responsible for validation 

analyses of model data. Asa Trainer was responsible for program execution, administration, 

and project management. Asa contributed significantly to authoring of the final report. 

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REFERENCES
*

Reference Description 

Reference A NIST 70NANB14H314 – Collaborative Agreement - Investigating the Impact 

of Standards-based Interoperability for Design to Manufacturing and Quality 

in the Supply Chain 

Reference B Contract Number SB1341-12-SE-0853 – NIST 3D Model-Based Engineering 

Product Manufacturing Information Validation and Conformance Testing 

Project - Phase 1 

Reference C Contract Number SB1341-14-SE-0061 – NIST 3D Model-Based Engineering Product 

Manufacturing Information Validation and Conformance Testing 

Project - Phase 2 

Reference D ISO 10303-242 “Managed Model Based 3D Engineering" [STEP AP 242] 

Reference E ANSI QIF 2.0, October 31, 2014 - http://qifstandards.org/download-qif/ 

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APPENDICES 

Appendix A: Mapping PMI into STEP and QIF 

Appendix A.1: Mapping GD&T into STEP and QIF 

PMI STEP AP242 ACIS QIF 

dimension types 

linear dimension dimensional_location spaxpmi_dimension LinearCharacteristicDefinitionBas 

eType 

radius dimension dimensional_size.name = "radius" spaxpmi_dimension RadiusCharacteristicDefinitionTy 

pe 

spherical radius dimension dimensional_size.name = "spherical 

radius" not covered 

diameter dimension dimensional_size.name = "diameter" spaxpmi_dimension DiameterCharacteristicDefinition 

Type 

spherical diameter dimension dimensional_size.name = "spherical 

diameter" not covered 

SphereFeatureDefinitionType<> 

Diameter [also in Spherical 

Segment] 

oriented dimension oriented_dimensional_location not covered OrientationCharacteristicDefinitio 

nBaseType 

curved dimension dimensional_location_with_path/dimen 

sional_size_with_path not covered CurvedLengthCharacteristicDefin itionType 

length dimension LengthCharacteristicDefinitionTy 

pe 

depth dimension dimensional_location.name = "depth" not covered DepthCharacteristicDefinitionTyp 

e 

width dimension dimensional_location.name = "width" not covered WidthCharacteristicDefinitionTyp 

e 

height dimension dimensional_location.name = "height" not covered HeightCharacteristicDefinitionTy 

pe 

thickness dimension dimension_size.name = "thickness" not covered ThicknessCharacteristicDefinition 

Type 

linear coordinate dimension dimensional_location.name = 

"coordinate" 

spaxpmi_dimension(DIMSUBTYPE_CO 

ORDDIM2D, 

DIMSUBTYPE_COORDDIM3D) 

LinearCoordinateCharacteristicD 

efinitionType 

angular coordinate dimension angular_location.name = "coordinate" 

spaxpmi_dimension(DIMSUBTYPE_CO 

ORDDIM2D, 

DIMSUBTYPE_COORDDIM3D) 

AngularCoordinateCharacteristic 

DefinitionType 

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PMI STEP AP242 ACIS QIF 

distance between dimension derived_shape_aspect/centre_of_sym 

metry not covered DistanceBetweenCharacteristicD efinitionType 

distance from dimension directed_dimensional_location not covered DistanceFromCharacteristicDefin 

itionType 

chord dimension dimensional_location.name = "chord" not covered ChordCharacteristicDefinitionTyp 

e 

square dimension SquareCharacteristicDefinitionTy 

pe 

angular dimension angular_location/angular_size spaxpmi_dimension (no way to specify 

which angle) 

AngleCharacteristicDefinitionTyp 

e 

angle-from dimension not covered not covered AngleFromCharacteristicDefinitio 

nType 

angle-between dimension derived_shape_aspect/centre_of_sym 

metry not covered AngleBetweenCharacteristicDefi nitionType 

dimension tolerance principle 

independency shape_dimension_representation.nam 

e = "independency" not covered <>EnvelopeRequirement(FALSE 

) 

envelope shape_dimension_representation.nam 

e = "envelope" not covered <>EnvelopeRequirement(TRUE) 

dimension values 

nominal value measure_representation_item.name = 

"nominal value" dimension value <>TargetValue 

nominal value with qualifier 

qualified_representation_item/type_qu 

alifier.name = 

"maximum"/"minimum"/"average" 

not covered <>TargetValue 

nominal value with plus/minus bounds plus_minus_tolerance not covered <>DefinedAsLimit(FALSE) 

value range measure_representation_item.name = 

"upper limit"/"lower limit" dimtol lower limit/dimtol upper limit <>DefinedAsLimit(TRUE) 

tolerance class (ISO 286) limits_and_fits not covered not covered 

basic/theoretical descriptive_representation_item.descri 

ption = "theoretical" dimension_type (dimtype_basic) <>DimensionType(BASIC) 

set <>DimensionType(SET) 

reference/auxiliary descriptive_representation_item.descri 

ption = "auxiliary" dimension_type (dimtype_reference) <>DimensionType(REFERENCE ) 

key characteristic <>KeyCharacteristic 

non-tolerance <>NonTolerance 

START ITEMS FROM TABLE 8 OF 

AP242 RECOMMENDED PRACTICES 

(from ISO ?) 

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PMI STEP AP242 ACIS QIF 

controlled radius descriptive_representation_item.descri 

ption = "controlled radius" not covered RadiusCharacteristicDefinitionTy pe<>ControlledRadius(TRUE) 

square descriptive_representation_item.descri 

ption = "square" not covered SquareCharacteristicDefinitionTy 

pe 

statistical tolerance descriptive_representation_item.descri 

ption = "statistical tolerance" dimension_type (dimtype_tolerance) 

CharacteristicDefinitionBaseType 

<>StatisticalCharacteristic(TRUE 

) 

continuous feature descriptive_representation_item.descri 

ption = "continuous feature" not covered UnitedFeature 

two point size descriptive_representation_item.descri 

ption = "two point size" (not Y14.5) not covered CharacteristicDirectionalZoneLim itType<>FromPoint,<>ToPoint 

local size defined by a sphere 

descriptive_representation_item.descri 

ption = "local size defined by sphere" 

(not Y14.5) 

not covered CharacteristicBaseType<>Descri 

ption 

least-squares association criterion 

descriptive_representation_item.descri 

ption = "least-squares association 

criterion" 

not covered 

XXXSubst.Feat.Algor.EnumType 

(LEASTSQUARES), for 

[Non]FeatureOfSize, Curve, 

Surface 

maximum inscribed association 

criterion 

descriptive_representation_item.descri 

ption = "maximum inscribed 

association criterion" 

not covered 

FeatureOfSizeSubstituteFeature 

AlgorithmEnumType(MAXINSCR 

IBED) 

minimum circumscribed association 

criterion 

descriptive_representation_item.descri 

ption = "minimum circumscribed 

association criterion" 

not covered 

FeatureOfSizeSubstituteFeature 

AlgorithmEnumType(MINCIRCU 

MSCRIBED) 

circumference diameter 

descriptive_representation_item.descri 

ption = "circumference diameter" (not 

Y14.5) 

not covered CharacteristicBaseType<>Descri 

ption 

area diameter descriptive_representation_item.descri 

ption = "area diameter" (not Y14.5) not covered CharacteristicBaseType<>Descri 

ption 

volume diameter descriptive_representation_item.descri 

ption = "volume diameter" (not Y14.5) not covered CharacteristicBaseType<>Descri 

ption 

maximum size descriptive_representation_item.descri 

ption = "maximum size" not covered <>MeasurementDirectiveEnum( 

MAXIMUM) 

minimum size descriptive_representation_item.descri 

ption = "minimum size" not covered <>MeasurementDirectiveEnum( MINIMUM) 

average size descriptive_representation_item.descri 

ption = "average size" not covered <>MeasurementDirectiveEnum(A VERAGE) 

median size descriptive_representation_item.descri 

ption = "median size" not covered CharacteristicDefinitionBaseType 

<>MedianFeature(TRUE) 

mid-range size descriptive_representation_item.descri 

ption = "mid-range size" not covered CharacteristicBaseType<>Descri ption 

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PMI STEP AP242 ACIS QIF 

range of sizes descriptive_representation_item.descri 

ption = "range of sizes" not covered CharacteristicBaseType<>Descri ption 

any restricted portion of feature 

descriptive_representation_item.descri 

ption = "any restricted portion of 

feature" 

not covered CharacteristicBaseType<>Descri 

ption 

any cross section descriptive_representation_item.descri 

ption = "any cross section" not covered SectionModifierEnumType(ACS) 

specific fixed cross section descriptive_representation_item.descri 

ption = "specific fixed cross section" not covered CharacteristicBaseType<>Descri 

ption 

common tolerance descriptive_representation_item.descri 

ption = "common tolerance" not covered CharacteristicDefinitionBaseType <>CommonZone(TRUE) 

free-state condition descriptive_representation_item.descri 

ption = "free-state condition" not covered CharacteristicDefinitionBaseType 

<>FreeState(TRUE) 

END TABLE 8 ITEMS 

united feature descriptive_representation_item.descri 

ption = "continuous feature" not covered CharacteristicDefinitionBaseType 

<>UnitedFeature(TRUE) 

dimension decimal places value_format_type_qualifier dimtol precision <>SpecifiedDecimalType@decim 

alPlaces 

datum datum spaxpmi_datum DatumDefinitionType 

datum feature datum_feature attrib_spaxpmi_datum FeatureNominal 

datum target placed_datum_target_feature spaxpmi_datumtgt DatumTargetDefinitionBaseType 

point axis2_placement_3d.name = 

"orientation" datum_target_type (dt_point) DatumTargetPointDefinitionType 

line axis2_placement_3d/length_measure_ 

with_unit.name = "target length" datum_target_type (dt_line) DatumTargetLineDefinitionType 

circular line axis2_placement_3d/length_measure_ 

with_unit.name = "circle diameter" 

DatumTargetCircularLineDefinitio 

nType 

rectangle axis2_placement_3d/length_measure_ 

with_unit.name = "target width" datum_target_type (dt_area_rect) DatumTargetRectangularAreaDe 

finitionType 

circle axis2_placement_3d/length_measure_ 

with_unit.name = "target diameter" datum_target_type (dt_area_circ) DatumTargetCircularAreaDefiniti 

onType 

cylindrical area advanced_face datum_target_type (dt_area_face) DatumTargetCylindricalAreaDefi 

nitionType 

sphere advanced_face datum_target_type (dt_area_face) DatumTargetSphereDefinitionTy 

pe 

area advanced_face datum_target_type (dt_area_face) DatumTargetIrregularAreaDefiniti 

onType 

movable datum target direction not covered MovableDatumTargetDirectionTy 

pe 

tolerance geometric_tolerance attrib_spaxpmi_geom_tol CharacteristicDefinitionBaseType 

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PMI STEP AP242 ACIS QIF 

tolerance types 

angularity angularity_tolerance tol_type (toltype_angularity) AngularityCharacteristicDefinition 

Type 

circular runout circular_runout_tolerance tol_type (toltype_runout_circular) CircularRunoutCharacteristicDefi 

nitionType 

circularity/roundness roundness_tolerance tol_type (toltype_circularity) CircularityCharacteristicDefinition 

Type 

coaxiality coaxiality_tolerance not covered *ConcentricityCharacteristicDefin 

itionType 

concentricity concentricity_tolerance tol_type (toltype_concentricity) ConcentricityCharacteristicDefinit 

ionType 

cylindricity cylindricity_tolerance tol_type (toltype_cylindricity) CylindricityCharacteristicDefinitio 

nType 

flatness flatness_tolerance tol_type (toltype_flatness) FlatnessCharacteristicDefinitionT 

ype 

parallelism parallelism_tolerance tol_type (toltype_parallelism) ParallelismCharacteristicDefinitio 

nType 

perpendicularity perpendicularity_tolerance tol_type (toltype_perpendicularity) PerpendicularityCharacteristicDe 

finitionType 

position position_tolerance tol_type (toltype_position) PositionCharacteristicDefinitionT 

ype 

profile of a line line_profile_tolerance tol_type (toltype_profile_line) LineProfileCharacteristicDefinitio 

nType 

profile of a point PointProfileCharacteristicDefiniti 

onType 

profile of a surface surface_profile_tolerance tol_type (toltype_profile_surf) SurfaceProfileCharacteristicDefin 

itionType 

straightness straightness_tolerance tol_type (toltype_straightness) StraightnessCharacteristicDefiniti 

onType 

symmetry symmetry_tolerance tol_type (toltype_symmetry) SymmetryCharacteristicDefinition 

Type 

texture SurfaceTextureCharacteristicDefi 

nitionType 

thread ThreadCharacteristicDefinitionTy 

pe 

total runout total_runout_tolerance tol_type (toltype_runout_total) TotalRunoutCharacteristicDefiniti 

onType 

tolerance zone 

diameter tolerance_zone_form.name = 

"cylindrical or circular" mod_dia_type (dm_dia) <>DiametricalZone 

33
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PMI STEP AP242 ACIS QIF 

spherical diameter tolerance_zone_form.name = 

"spherical" mod_dia_type (dm_spherical_dia) <>SphericalZone 

within a circle tolerance_zone_form.name = "within a 

circle" not covered CharacteristicCircularZoneLimitT 

ype 

rectangular tolerance zone tolerance_zone_form.name = 

"rectangular" not covered CharacteristicRectangularZoneLi mitType 

directional tolerance zone tolerance_zone_form.name = 

"directional" not covered CharacteristicDirectionalZoneLim itType 

between two concentric circles tolerance_zone_form.name = 

"between two concentric circles" not covered ZoneRadiiType 

between two equidistant curves tolerance_zone_form.name = 

"between two equidistant curves" not covered 

<>UnequallyDisposedZone [also 

explicit in Straightness, 

Circularity] 

within a cylinder tolerance_zone_form.name = "within a 

cylinder" not covered 

CylindricityCharacteristicNominal 

Type<>CharacteristicDirectional 

ZoneLimitType 

between two coaxial cylinders tolerance_zone_form.name = 

"between two coaxial cylinders" not covered ConcentricityCharacteristicNomin 

alType<>ZoneLimit 

between two equidistant surfaces tolerance_zone_form.name = 

"between two equidistant surfaces" not covered 

ConcentricityNonDiametricalZon 

eType [implicit in SurfaceProfile 

& Flatness, explicit in Cylindricity] 

runout runout_zone_definition not covered RunoutCharacteristicNominalBas 

eType<>ZoneDirection 

projected projected_zone_definition p_mag <>ProjectedToleranceZoneValue 

non-uniform non_uniform_zone_definition not covered SurfaceProfileNonUniformChara 

cteristicDefinitionType 

non-diametrical <>NonDiametricalZone [position, 

straightness, concentricity] 

elongated <>ElongatedZone [in 

PositionDiametricalZoneType] 

outer disposition <>OuterDisposition 

offest <>OffsetZone 

planar <>PlanarZone [orientation] 

tolerance modifiers (from RecPrac

6.9.3) 

any cross section geometric_tolerance_with_modifiers.m 

odifiers = .ANY_CROSS_SECTION. not covered <>IntersectionPlane 

common zone geometric_tolerance_with_modifiers.m 

odifiers = .COMMON_ZONE. not covered <>CommonZone(TRUE) 

34
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PMI STEP AP242 ACIS QIF 

each radial element geometric_tolerance_with_modifiers.m 

odifiers = .EACH_RADIAL_ELEMENT. not covered 

OrientationCharacteristicDefinitio 

nBaseType<>EachRadialElemen 

t(TRUE) 

free state geometric_tolerance_with_modifiers.m 

odifiers = .FREE_STATE. zone_modifier_type (zm_fs) <>FreeState(TRUE) 

least material requirement 

geometric_tolerance_with_modifiers.m 

odifiers = 

.LEAST_MATERIAL_REQUIREMENT. 

zone_modifier_type (zm_lmc) <>MaterialCondition(LEAST) 

line element geometric_tolerance_with_modifiers.m 

odifiers = .LINE_ELEMENT. not covered <>EachElement(TRUE) 

major diameter (of thread) geometric_tolerance_with_modifiers.m 

odifiers = .MAJOR_DIAMETER. not covered not covered 

maximum material requirement 

geometric_tolerance_with_modifiers.m 

odifiers = 

.MAXIMUM_MATERIAL_REQUIREME 

NT. 

zone_modifier_type (zm_mmc) <>MaterialCondition(MAXIMUM) 

minor diameter (of thread) geometric_tolerance_with_modifiers.m 

odifiers = .MINOR_DIAMETER. not covered not covered 

not convex geometric_tolerance_with_modifiers.m 

odifiers = .NOT_CONVEX. not covered FlatnessCharacteristicDefinitionT 

ype<>NotConvex(TRUE) 

pitch diameter geometric_tolerance_with_modifiers.m 

odifiers = .PITCH_DIAMETER. not covered ThreadCharacteristicActualType 

<>PitchDiameter 

reciprocity requirement 

geometric_tolerance_with_modifiers.m 

odifiers = 

.RECIPROCITY_REQUIREMENT. 

zone_modifier_type (zm_rfs) not covered 

separate requirement 

geometric_tolerance_with_modifiers.m 

odifiers = 

.SEPARATE_REQUIREMENT. 

not covered <>SeparateZone(TRUE) 

statistical tolerance 

geometric_tolerance_with_modifiers.m 

odifiers = 

.STATISTICAL_TOLERANCE. 

zone_modifier_type (zm_st) <>StatisticalCharacteristic(TRUE 

) 

tangent plane geometric_tolerance_with_modifiers.m 

odifiers = .TANGENT_PLANE. zone_modifier_type (zm_tp) <>TangentPlane(TRUE) 

collection plane <>CollectionPlane 

direction feature <>DirectionFeature 

orientation plane <>OrientationPlane 

orientation only <>OrientationOnly(TRUE) 

unequally-disposed tolerance unequally_disposed_geometric_tolera 

nce p_shift <>UnequallyDisposedZone 

tolerance with maximum value geometric_tolerance_with_maximum_t 

olerance not covered <>MaximumToleranceValue 

35
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PMI STEP AP242 ACIS QIF 

unit-basis tolerance 

length geometric_tolerance_with_defined_uni 

t runit1 ToleranceZonePerUnitLengthTyp e 

circular geometric_tolerance_with_defined_are 

a_unit.area_type = .CIRCULAR. runit1 ToleranceZonePerUnitArcLength 

rectangular geometric_tolerance_with_defined_are 

a_unit.area_type = .RECTANGULAR. runit1,runit2 ToleranceZonePerUnitAreaType 

square geometric_tolerance_with_defined_are 

a_unit.area_type = .SQUARE. runit1 ToleranceZonePerUnitAreaType 

per-unit-polar-area not covered not covered ToleranceZonePerUnitPolarArea 

Type 

per-unit-angle not covered not covered ToleranceZonePerUnitAngleTyp 

e 

composite tolerance geometric_tolerance_relationship attrib_spaxpmi_geom_tol CompositeSegmentDefinitionTyp 

eBase 

tolerance with datum references geometric_tolerance_with_datum_refer 

ence spaxpmi_drf XXX<>DatumReferenceFrameId 

datum reference datum_reference_compartment spaxpmi_dref <>DatumReferenceFrame 

<>Datum 

datum reference modifiers 

free state simple_datum_reference_modifier.mod 

ifiers = .FREE_STATE. not covered <>FreeState 

basic simple_datum_reference_modifier.mod 

ifiers = .BASIC. not covered DatumFeatureSimulatorModifierT 

ype<>BasicSize("BASIC") 

diametrical DatumFeatureSimulatorModifierT 

ype<>DiametricalSize 

linear DatumFeatureSimulatorModifierT 

ype<>LinearSize 

translation simple_datum_reference_modifier.mod 

ifiers = .TRANSLATION. not covered DatumTranslationType<>Datum Translation 

least material requirement 

simple_datum_reference_modifier.mod 

ifiers = 

.LEAST_MATERIAL_REQUIREMENT. 

datum_modifier_type 

(datum_modifier_lmc) <>MaterialModifier(LEAST) 

maximum material requirement 

simple_datum_reference_modifier.mod 

ifiers = 

.MAXIMUM_MATERIAL_REQUIREME 

NT. 

datum_modifier_type 

(datum_modifier_mmc) <>MaterialModifier(MAXIMUM) 

regardless <>MaterialModifier(REGARDLES 

S) 

point simple_datum_reference_modifier.mod 

ifiers = .POINT. not covered <>ReducedDatum(PT) 

36
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PMI STEP AP242 ACIS QIF 

line simple_datum_reference_modifier.mod 

ifiers = .LINE. not covered <>ReducedDatum(SL) 

plane simple_datum_reference_modifier.mod 

ifiers = .PLANE. not covered <>ReducedDatum(PL) 

orientation simple_datum_reference_modifier.mod 

ifiers = .ORIENTATION. not covered <>ConstrainOrientation(TRUE) 

any cross section simple_datum_reference_modifier.mod 

ifiers = .ANY_CROSS_SECTION. not covered <>SectionModifier(ACS) 

any longitudinal section 

simple_datum_reference_modifier.mod 

ifiers = 

.ANY_LONGITUDINAL_SECTION. 

not covered <>SectionModifier(ALS) 

contacting feature simple_datum_reference_modifier.mod 

ifiers = .CONTACTING_FEATURE. not covered <>ContactingFeature(TRUE) 

distance variable simple_datum_reference_modifier.mod 

ifiers = .DISTANCE_VARIABLE. not covered <>DistanceVariable(TRUE) 

constrain orientation <>ConstrainOrientation(TRUE) 

constrain subsequent <>ConstrainSubsequent(TRUE) 

fixed <>DatumFixed(TRUE) 

degree of freedom constraint x 

simple_datum_reference_modifier.mod 

ifiers = 

.DEGREE_OF_FREEDOM_CONSTR 

AINT_X. 

not covered DegreeOfFreedomEnumType(X) 

degree of freedom constraint y 

simple_datum_reference_modifier.mod 

ifiers = 

.DEGREE_OF_FREEDOM_CONSTR 

AINT_Y. 

not covered DegreeOfFreedomEnumType(Y) 

degree of freedom constraint z 

simple_datum_reference_modifier.mod 

ifiers = 

.DEGREE_OF_FREEDOM_CONSTR 

AINT_Z. 

not covered DegreeOfFreedomEnumType(Z) 

degree of freedom constraint u 

simple_datum_reference_modifier.mod 

ifiers = 

.DEGREE_OF_FREEDOM_CONSTR 

AINT_U. 

not covered DegreeOfFreedomEnumType(U) 

degree of freedom constraint v 

simple_datum_reference_modifier.mod 

ifiers = 

.DEGREE_OF_FREEDOM_CONSTR 

AINT_V. 

not covered DegreeOfFreedomEnumType(V) 

37
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PMI STEP AP242 ACIS QIF 

degree of freedom constraint w 

simple_datum_reference_modifier.mod 

ifiers = 

.DEGREE_OF_FREEDOM_CONSTR 

AINT_W. 

not covered DegreeOfFreedomEnumType(W) 

minor diameter simple_datum_reference_modifier.mod 

ifiers = .MINOR_DIAMETER. not covered DiameterModifierEnumType(LD) 

major diameter simple_datum_reference_modifier.mod 

ifiers = .MAJOR_DIAMETER. not covered DiameterModifierEnumType(MD) 

pitch diameter simple_datum_reference_modifier.mod 

ifiers = .PITCH_DIAMETER. not covered DiameterModifierEnumType(PD) 

with value datum_reference_modifier_with_value not covered DatumFeatureSimulatorModifierT 

ype<>LinearSize/DiametricalSize 

projected <>ProjectedDatum 

common datum/multiple datum

features datum_reference_element spaxpmi_dref <>CompoundDatum 

polyline presentation 

annotation_curve_occurrence/annotati 

on_fill_area_occurrence/annotation_sy 

mbol_occurrence/annotation_text_occ 

urrence/tessellated_annotation_occurr 

ence 

body/wire UserDefinedExtension 

Appendix A.2: Mapping Linkages into STEP and QIF
)

linkages STEP AP242 ACIS QIF 

PMI<->BREP 

BREP<-

geometric_item_specific_usage-

>shape_aspect<-PMI 

spacollection/entity PMI->Feature->Brep 

PMI<->polyline presentation 

PMI<-

draughting_model_item_association-

>annotation_occurrence/draughting_c 

allout 

not covered PMIDisplayType->PMI 

38
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This publication is available free of charge from: http://dx.doi.org/10.6028/NIST.GCR.16-003

Appendix A.3: Mapping PMI Features and User Defined Tolerances into STEP and QIF
)

PMI features STEP AP242 ACIS QIF 

arc feature not covered ArcFeatureXXXType 

circle feature not covered CircleFeatureXXXType 

compound feature not covered CompoundFeatureXXXType 

pattern feature not covered PatternFeatureXXXType 

profile group feature not covered ProfileGroupFeatureXXXType 

runout group feature not covered RunoutGroupFeatureXXXType 

cone feature not covered ConeFeatureXXXType 

conical segment feature not covered ConicalSegmentFeatureXXXTyp 

e 

cuboid (box) feature not covered CuboidFeatureXXXType 

cylinder feature not covered CylinderFeatureXXXType 

cylindrical segment feature not covered CylindricalSegmentFeatureXXXT 

ype 

edge point feature not covered EdgePointFeatureXXXType 

ellipse feature not covered EllipseFeatureXXXType 

elongated cylinder feature not covered ElongatedCylinderFeatureXXXTy 

pe 

extruded cross section feature not covered ExtrudedCrossSectionFeatureXX 

XType 

line feature not covered LineFeatureXXXType 

opposite (parallel) lines feature not covered OppositeLinesFeatureXXXType 

opposite (parallel) planes feature not covered OppositePlanesFeatureXXXType 

plane feature not covered PlaneFeatureXXXType 

point feature not covered PointFeatureXXXType 

sphere feature not covered SphereFeatureXXXType 

spherical segment feature not covered SphericalSegmentFeatureXXXTy 

pe 

39
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______________________________________________________________________________________ 

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PMI features STEP AP242 ACIS QIF 

surface of revolution feature not covered SurfaceOfRevolutionFeatureXXX 

Type 

threaded feature not covered ThreadedFeatureXXXType 

toroidal segment feature not covered ToroidalSegmentFeatureXXXTyp 

e 

torus feature not covered TorusFeatureXXXType 

user defined tolerance STEP AP242 ACIS QIF 

angular UserDefinedAngularCharacteristi 

cDefinitionType 

area 

UserDefinedAreaCharacteristicD 

efinitionType 

attribute UserDefinedAttributeCharacterist 

icDefinitionType 

force UserDefinedForceCharacteristic 

DefinitionType 

linear UserDefinedLinearCharacteristic 

DefinitionType 

mass 

UserDefinedMassCharacteristicD 

efinitionType 

pressure 

UserDefinedPressureCharacteris 

ticDefinitionType 

speed UserDefinedSpeedCharacteristic 

DefinitionType 

temperature UserDefinedTemperatureCharact 

eristicDefinitionType 

time UserDefinedTimeCharacteristicD 

efinitionType 

unit UserDefinedUnitCharacteristicDe 

finitionType 

40
!
Appendix A.4: Mapping of Boundary Representation (BREP) Geometry into STEP and QIF 
)

______________________________________________________________________________________ 

This publication is available free of charge from: http://dx.doi.org/10.6028/NIST.GCR.16-003

BREP STEP AP242 ACIS QIF 

topology 

solid manifold_solid_brep body/lump BodyType 

shell closed_shell/open_shell shell ShellType 

face advanced_face face FaceType 

mesh face tessellated_face not covered FaceMeshType 

loop face_bound/face_outer_bound/edge_l 

oop/vertex_loop loop LoopType 

mesh loop tessellated_wire not covered LoopMeshType 

edge oriented_edge/edge_curve edge/coedge EdgeType/CoEdgeType 

vertex vertex_point/cartesian_point vertex VertexType 

surface geometry 

cone conical_surface cone Cone23Type 

cylinder cylindrical_surface cone Cylinder23Type 

extruded surface surface_of_linear_extrusion spline Extrude23Type 

spline surface 

b_spline_surface/b_spline_surface_wit 

h_knots/rational_b_spline_surface/unif 

orm_surface/quasi_uniform_surface/be 

zier_surface 

spline Spline23Type 

nurbs 

b_spline_surface/b_spline_surface_wit 

h_knots/rational_b_spline_surface/unif 

orm_surface/quasi_uniform_surface/be 

zier_surface 

spline Nurbs23Type 

offset surface offset_surface off_spl_sur Offset23Type 

plane planar_surface plane Plane23Type 

revolved surface surface_of_revolution rot_spl_sur Revolution23Type 

sphere spherical_surface sphere Sphere23Type 

torus toroidal_surface torus Torus23Type 

ruled surface 

b_spline_surface/b_spline_surface_wit 

h_knots/rational_b_spline_surface/unif 

orm_surface/quasi_uniform_surface/be 

zier_surface 

spline Ruled23Type 

curve geometry 

circle circle ellipse ArcCircular13Type/ArcCircular12 

Type 

41
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BREP STEP AP242 ACIS QIF 

ellipse ellipse ellipse ArcConic13Type(ELLIPSE)/ArcC 

onic12Type(ELLIPSE) 

parabola parabola bs3_curve ArcConic13Type(PARABOLA)/Ar 

cConic12Type(PARABOLA) 

hyperbola hyperbola bs3_curve ArcConic13Type(HYPERBOLA)/ 

ArcConic12Type(HYPERBOLA) 

spline curve 

b_spline_curve/b_spline_curve_with_k 

nots/rational_b_spline_curve/uniform_ 

curve/quasi_uniform_curve/bezier_cur 

ve 

bs3_curve Spline13Type/Spline12Type 

nurbs 

b_spline_curve/b_spline_curve_with_k 

nots/rational_b_spline_curve/uniform_ 

curve/quasi_uniform_curve/bezier_cur 

ve 

bs3_curve Nurbs13Type/Nurbs12Type 

offset curve offset_curve_3d bs3_curve Nurbs13Type/Nurbs12Type 

line line straight Segment13Type/Segment12Typ 

e 

poly-line polyline body/wire Polyline13Type/Polyline12Type 

aggregate curve composite_curve body/wire Aggregate13Type/Aggregate12T 

ype 

Appendix A.5: Mapping Other MBD-related Items into STEP and QIF 

PMI STEP AP242 ACIS QIF

Notes text_literal not supported NoteType

Flag Notes not supported attrib_spaxpmi_flagnote NoteFlagType

Surface	Finish (roughness) not supported attrib_spaxpmi_roughness SurfaceTextureCharacteristicDefinitionType

Tables not supported not supported not supported

Global or General Tolerances not supported not supported not supported

Views draughting_model/camera_model spaxpmi_capture SavedViewType

42
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Appendix B: Validation Results for Test Models 

Appendix B.1: Validation Differences by PMI Category for Test Models STEP Model File Native 

CAD 

STEP 

Vendor 

Date DFS 

Count 

DTS 

Count 

DIM 

Count 

FCF 

Count 

NOTE 

Count 

Total 

Count 

DFS 

Diffs 

DTS 

Diffs 

DIM 

Diffs 

FCF 

Diffs 

NOTE 

Diffs 

Total 

Diffs 

827-9999-903.stp NX CoreTech 04/28/15 2 8 6 7 23 5 7 12 

827-9999-904.stp NX CoreTech 07/10/15 3 54 13 8 78 1 8 9 

nist_ctc_01_asme1_ct5210_rd_ct242repr.stp CATIA CoreTech 12/19/14 3 10 6 3 22 1 3 3 7 

nist_ctc_01_asme1_ct5210_rd_dk242repr.stp CATIA Datakit 02/16/15 3 10 6 3 22 4 3 7 

nist_ctc_01_asme1_nx800_rd_ct242repr.stp NX CoreTech 02/18/15 3 10 6 2 21 3 2 5 

nist_ctc_01_asme1_nx800_rd_nx.stp NX SPLM 11/04/15 3 10 6 2 21 9 2 11 

nist_ctc_01_asme1_nx800_rd_th.stp NX Theorem 11/10/15 3 10 6 2 21 1 2 3 

nist_ctc_02_asme1_ct5210_rc_ct242repr.stp CATIA CoreTech 12/19/14 10 9 8 22 1 50 10 9 8 22 1 50 

nist_ctc_02_asme1_ct5210_rc_dk242repr.stp CATIA Datakit 02/16/15 10 9 8 22 1 50 10 9 8 22 1 50 

nist_ctc_02_asme1_nx800_rc_ct242repr.stp NX CoreTech 02/18/15 7 9 7 22 1 46 7 9 7 22 1 46 

nist_ctc_02_asme1_nx800_rc_nx.stp NX SPLM 11/04/15 6 9 7 22 2 46 9 2 11 

nist_ctc_02_asme1_nx800_rc_th.stp NX Theorem 11/10/15 10 9 7 22 1 49 10 9 7 22 1 49 

nist_ctc_03_asme1_ct5210_rc_ct242repr.stp CATIA CoreTech 12/19/14 6 10 13 1 30 2 1 3 

nist_ctc_03_asme1_ct5210_rc_dk242repr.stp CATIA Datakit 02/16/15 6 10 13 1 30 2 1 3 

nist_ctc_03_asme1_nx800_rc_ct242repr.stp NX CoreTech 02/18/15 6 10 13 29 2 2 

nist_ctc_03_asme1_nx800_rc_nx.stp NX SPLM 11/04/15 6 10 13 29 2 2 

nist_ctc_03_asme1_nx800_rc_th.stp NX Theorem 11/10/15 6 10 13 29 1 1 

nist_ctc_04_asme1_ct5210_rd_ct242repr.stp CATIA CoreTech 12/19/14 8 10 5 1 24 3 1 4 

nist_ctc_04_asme1_ct5210_rd_dk242repr.stp CATIA Datakit 02/16/15 8 11 5 1 25 2 2 1 5 

nist_ctc_04_asme1_nx800_rd_ct242repr.stp NX CoreTech 02/18/15 8 10 5 23 3 1 4 

nist_ctc_04_asme1_nx800_rd_nx.stp NX SPLM 11/04/15 8 10 5 23 5 5 

nist_ctc_04_asme1_nx800_rd_th.stp NX Theorem 11/10/15 8 10 5 23 3 3 

nist_ctc_05_asme1_ct5210_rd_ct242repr.stp CATIA CoreTech 12/19/14 4 2 6 10 22 2 4 4 10 

nist_ctc_05_asme1_ct5210_rd_dk242repr.stp CATIA Datakit 02/16/15 4 2 6 10 22 2 3 3 8 

nist_ctc_05_asme1_nx800_rd_ct242repr.stp NX CoreTech 02/18/15 2 2 6 10 20 2 4 5 11 

nist_ctc_05_asme1_nx800_rd_nx.stp NX SPLM 11/04/15 2 2 6 10 2 22 2 4 2 8 

nist_ctc_05_asme1_nx800_rd_th.stp NX Theorem 11/10/15 4 2 6 10 22 2 2 4 4 12 

Counts: 149 55 280 299 39 800 38 55 100 107 39 329 

Percents: 

DFS = Datum Feature Symbol, DTS = Datum Tag Symbol, DIM = Dimension, FCF = Feature Control Frame 

43
!
 

 

Appendix B.2: Percent Clean (%) by PMI Category for Test Models
)

______________________________________________________________________________________ 

This publication is available free of charge from: http://dx.doi.org/10.6028/NIST.GCR.16-003

STEP Model File Native 

CAD 

STEP 

Vendor 

Date DFS 

Count 

DTS 

Count 

DIM 

Count 

FCF 

Count 

NOTE 

Count 

Total 

Count 

DFS 

Clean 

DTS 

Clean 

DIM 

Clean 

FCF 

Clean 

NOTE 

Clean 

Total 

Clean 

Clean 

Perc 

827-9999-903.stp NX CoreTech 04/28/15 2 8 6 7 23 2 0 3 6 0 11 48% 

827-9999-904.stp NX CoreTech 07/10/15 3 54 13 8 78 3 0 53 13 0 69 88% 

nist_ctc_01_asme1_ct5210_rd_ct242repr.stp CATIA CoreTech 12/19/14 3 10 6 3 22 2 0 7 6 0 15 68% 

nist_ctc_01_asme1_ct5210_rd_dk242repr.stp CATIA Datakit 02/16/15 3 10 6 3 22 3 0 6 6 0 15 68% 

nist_ctc_01_asme1_nx800_rd_ct242repr.stp NX CoreTech 02/18/15 3 10 6 2 21 3 0 7 6 0 16 76% 

nist_ctc_01_asme1_nx800_rd_nx.stp NX SPLM 11/04/15 3 10 6 2 21 3 0 1 6 0 10 48% 

nist_ctc_01_asme1_nx800_rd_th.stp NX Theorem 11/10/15 3 10 6 2 21 3 0 9 6 0 18 86% 

nist_ctc_02_asme1_ct5210_rc_ct242repr.stp CATIA CoreTech 12/19/14 10 9 8 22 1 50 0 0 0 0 0 0 0% 

nist_ctc_02_asme1_ct5210_rc_dk242repr.stp CATIA Datakit 02/16/15 10 9 8 22 1 50 0 0 0 0 0 0 0% 

nist_ctc_02_asme1_nx800_rc_ct242repr.stp NX CoreTech 02/18/15 7 9 7 22 1 46 0 0 0 0 0 0 0% 

nist_ctc_02_asme1_nx800_rc_nx.stp NX SPLM 11/04/15 6 9 7 22 2 46 6 0 7 22 0 35 76% 

nist_ctc_02_asme1_nx800_rc_th.stp NX Theorem 11/10/15 10 9 7 22 1 49 0 0 0 0 0 0 0% 

nist_ctc_03_asme1_ct5210_rc_ct242repr.stp CATIA CoreTech 12/19/14 6 10 13 1 30 6 0 8 13 0 27 90% 

nist_ctc_03_asme1_ct5210_rc_dk242repr.stp CATIA Datakit 02/16/15 6 10 13 1 30 6 0 8 13 0 27 90% 

nist_ctc_03_asme1_nx800_rc_ct242repr.stp NX CoreTech 02/18/15 6 10 13 29 6 0 8 13 0 27 93% 

nist_ctc_03_asme1_nx800_rc_nx.stp NX SPLM 11/04/15 6 10 13 29 6 0 8 13 0 27 93% 

nist_ctc_03_asme1_nx800_rc_th.stp NX Theorem 11/10/15 6 10 13 29 6 0 9 13 0 28 97% 

nist_ctc_04_asme1_ct5210_rd_ct242repr.stp CATIA CoreTech 12/19/14 8 10 5 1 24 8 0 7 5 0 20 83% 

nist_ctc_04_asme1_ct5210_rd_dk242repr.stp CATIA Datakit 02/16/15 8 11 5 1 25 8 0 9 3 0 20 80% 

nist_ctc_04_asme1_nx800_rd_ct242repr.stp NX CoreTech 02/18/15 8 10 5 23 8 0 7 4 0 19 83% 

nist_ctc_04_asme1_nx800_rd_nx.stp NX SPLM 11/04/15 8 10 5 23 8 0 5 5 0 18 78% 

nist_ctc_04_asme1_nx800_rd_th.stp NX Theorem 11/10/15 8 10 5 23 8 0 7 5 0 20 87% 

nist_ctc_05_asme1_ct5210_rd_ct242repr.stp CATIA CoreTech 12/19/14 4 2 6 10 22 4 0 2 6 0 12 55% 

nist_ctc_05_asme1_ct5210_rd_dk242repr.stp CATIA Datakit 02/16/15 4 2 6 10 22 4 0 3 7 0 14 64% 

nist_ctc_05_asme1_nx800_rd_ct242repr.stp NX CoreTech 02/18/15 2 2 6 10 20 2 0 2 5 0 9 45% 

nist_ctc_05_asme1_nx800_rd_nx.stp NX SPLM 11/04/15 2 2 6 10 2 22 2 0 2 10 0 14 64% 

nist_ctc_05_asme1_nx800_rd_th.stp NX Theorem 11/10/15 4 2 6 10 22 2 0 2 6 0 10 45% 

Counts: 149 55 280 299 39 800 107 0 178 186 0 471 59% 

Percents: 72% 0% 64% 62% 0% 59% 

DFS = Datum Feature Symbol, DTS = Datum Tag Symbol, DIM = Dimension, FCF = Feature Control Frame 

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