# Presentation: 363822

## NROCJune 27, 2002

_**NROC**_**June 27, 2002**

**Mike Nix, MSFC**
**Doug Morris, LaRC**
**Ray Evans, KSC**

## NROC Briefing Contents

- Purpose of Briefing
- Reliability, Maintainability and Supportability - General Considerations
- Intercenter Systems Analysis Team (ISAT)
- COMET/OCM - Ops and Support Costing
- RMAT - Failure and Maintenance Rates
- The  Nature of O&M and KSC Expertise
- Integration (N)
- Facilities Cost Estimating
- Conclusion - NROC

## Purpose of Briefing

- Explain the application of the NROC model to RM&S and Operations Analyses of Future Launch Systems

## Reliability, Maintenance and Support

- Reliability is_** the primary**_ characteristic in determining the maintenance  and  support requirements for system operation.
- Almost equal is Complexity - the number of different commodities, hazardous and toxic materials, confined spaces, lack of commonality and accessibility - these directly affect ...
- Maintainability - the ease with which this maintenance is  performed, which with the above drives the need for
- Support - the provision of those things which are needed to perform the maintenance and operate the system -  people, equipment, consumables, spares and facilities - and how easy or difficult this is determined by Supportability

## Separating the Concepts

- From RAM Dictionary (1988): “.... complete system may require ... for its _**operation and support**_....”
- Support (supportability) is distinguished from Maintenance (Maintainability) and Operation (Operability) as follows:
- Support is the provision of the resources necessary to operate or maintain systems
- Supportability is system characteristic that determines the ease with which resources are provided
- Maintenance is the utilization of the resources to restore or sustain systems to or in a functional state
- Maintainability is the ease with which restoration or sustainment is performed
- Operation is the utilization of the resources to cause systems to perform function
- Operability is the ease with which function is caused

## Measuring RM&S 

- What tells us how reliable, maintainable, supportable (or operable) a system is?
- Reliability is generally indicated by MTBF, MTBMA, MTBOH, MMA/Cycle
- Maintainability is measured by MTTR,  MMH/MA
- Supportability is measured by things like
- Crew sizes
- Task times
- GSE requirements
- Facilities requirements
- Spares requirements
- Consumables and commodities
- Administrative burden
- Logistics burden

## Modeling RM&S/Operations at Conceptual Levels

- In assessing the RM&S of launch system architectures in the conceptual stages, we are presented with several problems.
- Very little detail in the “design” information - generally limited to
- Weight statements
- Geometric descriptions
- Descriptions of technologies
-  Scarcity of “accepted” and established processes
- Lack of tools that are effective and credible
- Uncertainty in the data and in the output of the tools
- The response is to develop new or adapt approaches, methods and tools  to meet the need of estimating how reliable, maintainable,supportable and operable these  architectures are likely to be

## The Approach to RM&S Modeling in NROC

- The RM&S of a system are manifested in several ways other than by pure numbers (as indicated earlier):
- Reliability by the amount of maintenance that must be performed between cycles
- Maintainability by task times, crew sizes and turn times
- Supportability by the cost to provide facilities, consumables, equipment, training, etc
- If we can model these things, we can infer the RM&S of a system and can compare one system with another
- The ultimate measure of RM&S is the cost to operate a system BUT we must understand more than the bottom line

## Operations Parameters - Pontificating

- Measuring the effects of RM&S changes due to technology and architecture
_**All**_ costs for space launch operations can be traced to the following elements, most of which are included either in the series of tasks required to prepare a vehicle for launch and to conduct mission ops, or in the supporting functions:
- People (skill level, training, overhead etc) - accounting for ALL
- Time (task duration) - Critical path tasks drive TAT
- Facilities (including all supporting functions)
- Infrastructure
- GSE
- Consumables
- Utilities
- Replacement hardware and spares
- Other (insurance, fees, taxes, etc)
- How to estimate values for these parameters at any given point in the development phase and incorporate probabilistic considerations

## Conceptual Operations Manpower Estimating Tool and Operations Cost Model (COMET/OCM) 

- Validated, easily integrated (Excel) and fills the need for estimating recurring costs at conceptual level
- Based on data from STS and Titan
- Estimates effort required to operate Manned/Reusable, Unmanned/Reusable, Manned/Expendable systems and Unmanned/Expendable systems (basic cost drivers)
- Developed in 1994
- Intended to integrate all launch system elements - launch and flight operations (KSC/ and JSC) - at conceptual level
- Big Pieces Missing
- Depot Maintenance	Engine Depot Maintenance	MSFC
- SSC			Thiokol			MAF
- Costs of Upper Stages

## What Does COMET/OCM DO?

- COMET Estimates Headcount needed to “process” and “fly” a conceptual vehicle
- User describes concept by answering specific questions about the vehicle and the flight profile
- COMET matches the vehicle elements to a table of data on Shuttle and Titan manpower and estimates the vehicle processing headcount based on type and number of elements
- COMET uses the number of events in the flight profile to estimate the manpower required for flight planning
- OCM uses ratio analysis to estimate the HC for other supporting functions for both ground and flight operations
- OCM adds consumables, spares, wraps, network support
- OCM includes learning curves, ramp up to steady state conditions and other considerations to capture a broad picture of launch system operations
- OCM produces per year and per flight costs and “fixed” and “variable” costs for a range of flight rates

## Flight Rates

- COMET/OCM does not input vehicle flight rate capability
- Common misunderstanding
- The 4 flight rates that are input are DEMAND rates - what _**has**_ to be flown -  not what _**can**_ be flown
- OCM uses baseline Shuttle/ELV flight rate capability to adjust HCs to support these rates
- Implicit assumption is that either the individual vehicles CAN be turned fast enough OR
- ENOUGH vehicles will be available

## COMET Ground & Flight Operations Interview Input Format - Description of Vehicle & Mission

## User Selected Flight Events Table (Partial)

- There are three mission phases:
- 	Ascent
- 	On-orbit
- 	Descent
- User indicates number of times an
- Event occurs during phase. Tool
- automatically sums the events
- And transfers the number to the
- COMET sheet.This drives the
- Flight Planning HC,

## COMET Headcount Results

- As previously noted, the basic headcount is predicated on 8 flights/year

- Using the exponent and multiplier
- COMET Estimates HC for different
-  FRs

## COMET Headcount Equation for Flight Planning 

- COMET Headcount Equation for Flight Planning

## OCM Ratio Analysis for Other Operations Elements

## OCM Inputs

## OCM Cost Outputs

## OCM Regression Analysis - Launch Cost Summary

- The intercept of this curve is the Fixed Cost per Year
- The slope is the Variable Cost per flight
- NOT TRUE “_FIXED_” OR “_VARIABLE_” - Math constructs

## Disadvantages

- COMET/OCM grounded in Shuttle and Titan architectures
- COMET/OCM does generate a more complete picture of operations (supportability) than a pure “Processing Model” HOWEVER
- Lacks level of detail to assess effects of technologies on subsystems
- No provision for how introduction of new technologies changes nature of how maintenance and operations are conducted
- No provision for new ground-side technologies
- Difficult to model architectures like Bimese TSTO, which is essentially 2 orbiters flying every flight
- The inability to penetrate to the vehicle subsystem level led us to look for ways to increase the level of detail while retaining the broad scope of the original model. We found an answer:
- Integrate RMAT with COME/OCM and add Operations Experience and Expert Input directly from KSC

## Modifications To COMET/OCM More Detailed Level of Analysis

-   RMAT WBS coupled with COMET/OCM  processing elements/ subelements
- 	- RMAT applicable only to OPF processing (more or less) BUT
- 	- OCM adds other vehicle and operations elements
-   RMAT determines O &M parameters by vehicle subsystem
-   Expert judgment (KSC) on effects of technology on the “nature” of the O &M
-  Vehicle Subsystem estimates limited to the effects on receiving, inspection, and preparation and repair in vehicle (orbiter) processing
-   Other operations element effects estimated by KSC at the vehicle level (see “N” sheet)

## COMET Launch & Flight Operations Elements

## RMAT Input

- RMAT takes us from Shuttle Orbiter to the Reference Vehicle
- On a Subsystem by Subsystem Basis through Certain Parameters

## Slide 25

## RMAT Vehicle WBS and Subsystem Parameters - Revised

- Example: Equation for Engine Maintenance Burden:
- Burden=23629+0.36*(Subsyst Wt)-7511*(No. Engines)+822*(No. Engines)*(No.Engines)

## The Nature of O&M - DriversThe Next Consideration

- In introducing a new technology into a conceptual vehicle subsystem two things in general happen that affect O & M
- Vehicle shrinks or grows affecting the subsystem parameters (surface area, weight, number engines)
- The Nature of O&M may change - the way things are done
- Alleviate hazard (eliminating hypergols) - improving safety
- Simplify the subsystem
- Different materials - different processes
- Less cleanliness required
- The first accounted for by weight and sizing models ( e.g., INTROS) once the reference vehicle has been established via RMAT
- The second by direct input from KSC operations subsystem experts estimating the degree to which the technology affects the O&M process
- These inputs (RMAT, INTROS and KSC Expert Judgment) must be integrated into COMET/OCM
- Process/Component/Human Reliability effects confounded in both COMET/OCM and RMAT data and outputs

## Input From Operations Experts - KSC

- We needed means of introducing the engineering judgment  of “hands-on” operations personnel at KSC
- Process involves interchanges between Shuttle subsystem experts and technologists to understand
- The context into which the technology is introduced - the operations and maintenance of the vehicle subsystem
- The effect the technology will have on the nature of the subsystem O&M - how it changes the way in which the subsystem is operated and maintained
- An iterative process - similar to that established in the aero ISAT activities
- Subsystems experts then estimate the degree to which the technology changes O&M - does the burden increase or decrease - by how much
- Often able to draw on previous studies of Shuttle upgrades
- KSC Lead is Ray Evans

## Technology Inputs 

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- Currently 69
- technologies
- (with some duplication)

## Integration Sheet (N)

## N Sheet Output

## Vehicle Processing Headcount Adjustments

## Facilities and Other Support Functions

- With RMAT and KSC Input, we were able to add reliability and maintainability considerations to the supportability coverage of COMET/OCM
- We needed another element to broaden the inclusion of supportability
- In the 1996 HRST Operations Assessment, a facilities cost estimating worksheet was integrated into COMET/OCM and correlated to the architecture and vehicle characteristics
- In  the 2000 ISAT activities, the facilities were further indexed to TATs and Flight Rates so that in the current model, the quantity and kind of facilities needed to support a given architecture can be estimated over a range of flight rates
- Such diverse facilities as those for Propellant Densification, Hypergol Maintenance, Orbiter Processing and the Mobile Launch Platform are included
- To support the economics model, facilities cost are estimated as both fixed per year and variable by flight over a range of flight rates
- The”variable” and “fixed” costs allow user to calculate the facilitization costs to support any flight rate
- Currently in revision

## For the Visually Oriented

## NROC Flow Chart

## Conclusion

- By incorporating RMAT into COMET/OCM with KSC input, RM&S are given consideration down to the vehicle subsystem level
- By incorporating the facilities cost estimating capability, integrated with vehicle and architecture characteristics, the supportability analysis capability of COMET/OCM has been enhanced
- While NROC does not provide specific RM&S estimates, it allows the user to gain insight into the effects changes in those inherent characteristics have on conceptual systems  - whether at the architecture or technology level
- NROC is not intended to be a tool for use with detailed design data - it was intended to provide a rational assessment of concepts when more “traditional” and textbook methods could not be applied.
- NROC applies a complementary approach to and supplements AATe and other tools
- Limited by requirement to automate and integrate - shortcuts, reference vehicle “library”
- Best approach to RM&S/Operations analysis continues to be via a tool set rather than a single tool

## Near Term Modifications

- Turnaround Times
- Manpower vs TAT Toggle (increase Processing HC to reduce TAT)
- Driven by vehicle characteristics such as reliability and maintainability (accessibility) - how fast _CAN_ the vehicle be turned around
- Driven by demand - how fast does it _NEED_ to be turned around
- Driven by economics - how fast does it _PAY_ to turn it around
-   Update Shuttle and ELV Cost Data
-   Account for the OMDP, Engine Depot, MSFC, SSC, Thiokol, MAF and other KSC/JSC elements that support Shuttle
-   Account for improved GSE, inspection and checkout technologies, changes in management philosophy
-  Upgrade/Update Facilities Cost Estimating
-  Add “Aircraft Operations” capability
-  Consider such differences as Internal tanks - not only processing but purging and safing, insulation maintenance
-  Stochastic modeling capability
-  Upgrade subsystem parameter relationships to estimate maintenance burden

## Turnaround Time (TAT) Related to Maintainability/Accessibility

- TAT

- Resources Applied

- Given Subsystem/Component Reliabilities, Minimum TAT Determined by Maintainability/
- Accessibility Characteristics of Vehicle and Supporting Infrastructure

- How Fast _**Can**_ The Vehicle Be Turned Around

## Turnaround Time (TAT) Related To Demand/Mission Need

- TAT

- Flight Rate per Vehicle in Response to Demand

- How Fast Is It _**Necessary**_ To Turn the Vehicle Around

- Demand Would Drive TAT as Low as Necessary
- If Possible

- Minimum TAT to Meet Demand - May Not Be Achievable
- Additional Vehicles Required (Fleet Size)

- Maximum
- Demand

- Minimum
- TAT

## Turnaround Time (TAT) Related to ROI

- TAT

- ROI

- How Fast Does It _**Pay**_ to Turn the Vehicle Around

- Maximum ROI
- Possible As a Function of TAT

- Minimum
- TAT

## COMET Headcount Database (1992 Shuttle/Atlas/Titan)

## COMET/OCM Launch Operations Element Definitions

##  COMET/OCMFlight Operations Element Definitions