JJ & EResearch

Specialty Engineering as an Element of Systems Engineering

INCOSE MEETING (Enchantment Chapter)

August 9, 2006

Murray ElowitzJJ & E Research Corp

11045 Greenview NE

Albuquerque, NM 87111

(505) 856-7247

melowitz@comcast.net

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JJ & EResearch

To discuss how System Engineers include SPECIALTY ENGINEERING in their project

• Defining Specialty Engineering• Where it fits into System Engineering• Example 1: Meeting spec• Example 2: More subtle

Purpose

Goal: Maximize effectiveness of specialties to support program success

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JJ & EResearch

Exercise for the student – define products of each specialty

Defining Specialty Engineering

• Murray’s Definition (Today’s version) –

Specialty Engineering is the collection of those narrow disciplines that are needed to engineer a complete system

Some specialty engineering has deliverable functional products,

Some specialty engineering is analytic.

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JJ & EResearchWhat are specialties

SAMPLE LIST (For integrated hardware/software/data systems)

• RELIABILITY, MAINTAINABILITY, AVAILABILITY• Human Factors• Safety• Electromagnetic Effects• Facilities

Some people include• Logistics

Exercise for the student – Name other specialties

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JJ & EResearch

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JJ & EResearchDefinitions

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JJ & EResearch

Typical Org Chart

Program Manager

System Engineer Hardware Software Logistics

Specialties

RMA

Safety

Human Factors

Alternate

Etc

Specialties under System Engineering - Allows careful direction to get to needed results

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JJ & EResearchCharacteristics

• Why distinguish the specialties from System Engineering?– Usually a narrow discipline; e.g., RMA– In project team, hard to level load manpower – Practitioners usually want their own identity

• Why place specialties under System Engineering?– For early phases (Concept Definition through DemVal)

• SE needs to control or task the specialties

• Knows where the problems and issues are

• Understands and performs top-level trades

Exercise for the student – Give more reasons

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JJ & EResearchIn System Engineering Process

SystemRequirements

SpecialtyRequire

SystemDesign

SpecialtyDesign

SystemAnalysis

SpecialtyAnalysis

PreliminaryDesign

SpecialtyDes, Anal

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JJ & EResearchExample 1: Meeting spec

• Critical Requirement is reliability of commercial aircraft• After initial modeling, AVIONICS is critical segment

ModelReliability

DesignDesignIteration

Add DetailReliability

DesignIteration

Reflect results

Two sides to iteration• Underdesign drives loss of sales• Underdesign drives warranty costs• Overdesign drives cost, possibility loss of sales

Did Not Meet Specs

Did Not Meet Specs

Add DetailReliability OK

Meets Specs

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JJ & EResearchProcess

ReliabilityHandbook

Model System Look upFailure Rates

Crunch Present

Examples of the kind of system level trades needed instantly

System engineer needs special studiesWhat is sensitivity of R to tolerance on controlled temperature?

If tightening up on Temp increases vibration, what is system R?

If we replace component C with a cheaper one, but use redundancy, will we still meet R spec?

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JJ & EResearchExample 2: More subtle

• Availability – Requires reliability calculations and corresponding MTTR’s

• What if the baseline design makes component K hard to replace, creating a large MTTR?– System tradeoffs may involve lowering MTTR on other

components, improving R of component K or others, major design changes to lower K’s MTTR, and so on (and on)

– System engineer needs to direct Specialty Engineering to solve the right problem

• Then SE may need to address whether spec is reasonable

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JJ & EResearchSystem Engineering Golden Rules

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JJ & EResearchSummary

• In the early phases of a program, System Engineering needs tight control over Specialties– Needs to direct resources– Needs to prioritize– Needs responsiveness

• Putting Specialties under System Engineer provides needed control

• System Engineer needs to know the capabilities and limitations of each specialty