# Presentation: 547335

## Operations Analysis Methods/Tools forConceptual Design

**Presented at**
**Operations Analysis Tools and Processes**
**Technology Interchange Meeting**
**KSC**
**6/27/2002**
**W. Douglas Morris**
**Langley Research Center**

## Langley Models/Tools Agenda

- •  Background
- •  Approach
- •  Methods/Tools
-     •  RMAT
-     •  Logistics
-     •  Simulation
-     •  Data Bases
- •  Current Support
- •  Future Work

## Background

- •  Operations Analysis as a discipline became a part of the branch’s studies shortly after the Shuttle began to fly.
- •  At that time, analysis was primarily intuitive.
- 	•  No visable linkage between the design  and its support
- 	•  Much arm waving analysis.
- •  A primary focus of Vehicle Analysis Branch (VAB) is to perform _systems analysis studies_ of new launch concepts in order to:
- 	•  _Assess_ their _feasibility_
- 	•  To _identify_ high payoff technologies
- •  Initial Operations and Support studies:
- 	•  Principle tool- _Discrete Event Modeling_
- 	•  Principle problem- _Lack of data_ bases to support the model
- •  The relationship between design and  O&S requirements are _empirically driven_

## Approach

**Approach**
- _Vehicle Centric_- start with the design
- Move _aircraft techniques_ up the development curve
- Use methods which _mimic_ those techniques
- _Tailored_ to the level of information available
- _Comparability Analysis_ – define future system support requirements in terms of existing systems support requirements
- Establishes _reasonable bounds_ on assessments
- Adds _credibility_ and confidence to the results
- Criteria:
- Work with _conceptual level data_
- _Link_ the _design_ to the O&S _environment_
- Where possible, based on _historical data_
**Underlying**** Assumption**
- Support for a system is a function of:
- Design – characterized by the R&M
- Support Concept – characterized by the maintenance policy

## Scope of Analysis

## Analysis Methods

**R&M**
- Estimates reliability and maintainability requirements for new concepts
- Based on comparability to historical aircraft and Shuttle RRM data
- Tailored to work with products from conceptual design studies
- Works at subsystem level
**Logistics (Supportability)**
- Defines logistics support requirements in terms of training, spares, transportation, etc.
- Based on historical Shuttle and aircraft logistics support parameters
- Based on vehicle and mission definitions
**Simulation**
- Integrates results in operating scenario
- Introduces effects variance in the support parameters
- Defines resource requirements and flight rate capabilities when multiple demands are made on limited resources

## Single-Stage Vehicle (SSV) Concept

## Operating Scenario

**Operating Scenario**

## Reliability & Maintainability Analysis Tool (RMAT)

## Operations and Support Drivers

**Maintenance Actions**
**(R&M)**
- MTBMA
- MH/MA
- Critical failure rate
- Etc.

**Maintenance **
**Policy**
- Ratio scheduled to unscheduled maintenance
- Crew size
- Ground power-on time (GPOT)
- Etc.

## Maintenance Burden as a Function of R&M and Maintenance Concept Characteristics

## Maintenance Burden

## Logistics (Supportability) Model

## Simulation Modeling for Operations

## Databases

## Inputs, Outputs, Judgement & AEE

- •  Input:
- 	•  From CONSIZ, INTROS, and any other like weights & sizing program
- 	•  From program requirements (flight rate)
- 	•  From technologists, designers, operations experts, anyone with an 		   opinion.
- •  Output .....it depends, but primarily estimates of:
- 	•  maintenance burden by subsystem for a typical turnaround operation
- 	•  staffing requirements to meet flight rates
- 	•  failure rates, repair times
- •  Judgement:
- 	•  All programs require judgements
- 	•  RMAT _provides bounds_ and _guidance_ to aid in developing estimates
- 	•  Isolates estimates to effects on a subsystem and reduces variance
- 	•  Decisions made _in context_ by working with the technologist.
- •  AEE:
- 	•  Ready, but need definition of what is required to implement.

## Update & Status

- •  RMAT converted from the original Basic Software into Visual Basic
- •  Modified to perform parametric studies using Excel input and output.
- 	•  Allows input of multiple runs from spreadsheet
- 	•  Proration equations used to capture variance due to size, weight,
-               etc. and to apply the variance seen in aircraft to Shuttle parameters.
- •  Developed TPS damage rates based on type and coverage area.
- •  Modified to accepted Serial time allowance by subsystem.(hazardous, etc.)
- •  Automated manpower leveling.(more efficient staffing levels)
-   Note: Maintenance burden is based on per flight while staffing is based on a
-   monthly burden.  Significance is that it captures benefits of shared support.
- •  Forms the basis of an integrated tool to provide O&S and cost feedback in our design process.
- 	•  To provide direct integration with complementary tools.
- 	•  Ultimately to provide a web based analysis tool.

## Summary

- •  _RMAT_ is an analysis tool _used to estimate the reliability and maintainability_
- requirements of new concepts based on comparability to aircraft and Shuttle
- support  requirements.
- •Provides _quantifiable_ metrics
- 	•  _Traceable_ to real systems
- 	•  Can be used as _goals/specification_ for new technologies/designs
- 	•  Provides _initial allocation_ of R&M parameters for new designs.
- •  Can be used to provide “quick look” snapshot of technology effects on support requirements.
- •  By itself RMAT is _not a cost model_, but it does _provide information needed for costing_.  In _combination_ with the Logistics Cost Model (LCM) it _can be used_ for estimating _O&S costs_.
- •  RMAT uses a _proven process_ for analysis--_needs better data_ to be most effective

## Future Work

- •  Developing a minimum processing time option based on Shuttle information.  (Shuttle headcounts as benchmarks, size adjusted, defaults and user defined limits.)
- •  Using Air Force Mishap data to develop relationships to estimate probabilities of vehicle loss by subsystem.
- •  Continue model development to provide easier use and a more integrated analysis.
- •  Integrate RMAT/LCM into Model Center