“A Systems Engineering Approach For Balancing Powered Trailer Requirements” Dana Peterson (CSEP Acq) [email protected] (314) 553-4599

“A Systems Engineering Approach For Balancing Powered Trailer Requirements”

Dana Peterson (CSEP Acq) [email protected]

(314) 553-4599

mailto:[email protected]

• Illustrate a sample of Systems Engineering tools used on the Powered Trailer project to:– Resolve requirement issues– Understand relationships between

requirements– Prioritize requirements– Get consensus on the best technology

options– Provide the best “balanced” overall

solution

Purpose of Presentation

2INCOSE BRIEF @ DRS Technologies

• Improve combined truck and trailer grade climbing and mobility in soft soil terrain conditions

• Provide cargo and health status reporting over the C4I network

• Provide limited trailer self-mobility for climbing aircraft/ship ramps under operator control

• Provide on-board DC/AC export power for powering shelters and other equipment

Powered Trailer Project Goals

Powered Trailer

Focus is on Trailer Drive Technologies


• Requirements Traceability/ Rationale Matrix (RTRM)

• N2 Diagram• Analytic Hierarchy Process

(AHP)• Quality Function Deployment

(QFD)• Morphological Analysis (MA)• Architecture Views• Trade Study• Sensitivity Analysis

• Affinity Diagram• Tree Diagram• Fishbone Diagram• Digraph• Blueprinting• Arrow Diagram• Matrix Diagram• Relations Diagram• Process Decision Program Chart• Flow Diagram• Context Diagram• Pugh Matrix• Specification

Sample SE Tools


Systems Engineering Approach

PerformanceSpec

UserRequirements

Requirements Traceability/Rationale Matrix (RTRM)

RequirementPrioritizationQFD HouseOf Quality

Power TrailerDesign Alternatives

Mobility Analysis

Trade Studies-Performance-Payload-C-130 Transport-R&M-Cost -Schedule

Technology Options

Sensitivity Analysis

PreferredSolution

AHP MA

LegendAHP = Analytical Hierarchy Process

QFD = Quality Function Deployment

MA = Morphological Analysis

An Iterative Hierarchical Process That Provides the Best Overall Requirements Balance

• Many requirements in diverse functional areas

• A lot of stakeholders involved• Tools are needed to balance requirements

and validate concept prior to project execution

• Cost and schedule are receiving a lot more attention

Multi-Attribute Criteria Problem

Performance

Cos

t

Schedule


Solution Synthesis is Becoming More Challenging

Design for AdaptabilityDesign for Adaptability

Performance

Cos

t

Schedule

Design for Dynamic Value

Open Architecture

Modular Systems Approach Design To Cost

Spiral Development Rapid Response

Eco-Consciousness

People Resources

Company Mergers

Reorganization

Economic

Political

Cultural

Technology Advances

Part Obsolescence

Robust Design Techniques

Six Sigma

Agile DesignSecurity


• Prioritizing Requirements:– Spiral 1, 2, 3 Evolution– Threshold Vs Objective– Key Performance Parameters Vs Key

System Attributes Vs Additional Attributes– Tier Levels 1, 2, 3, 4

• Asking:– What Is Possible?– What Can Be Done Within Program

Constraints and Current Technology?– What Are The Tradeoffs?

Customers Now:

Provide Me With The Best Balanced Solution!


Item Reqmt/Short Description

Source Comments/Requirements Rationale Spiral 1

Spiral 2

Spiral 3 Prod

Draft Trailer Requirement based on FTTS ORD unless specified otherwise

78 30% Side Slope Derived from ORD lines 300 - 304

The MSV at GCW must negotiate the 30% side slope. The companion trailer is assumed coupled to the truck. This requirement must be met with either side of the vehicle facing uphill. At what speed does this need to be meet? Definitely need to check stability

xThe FTTS-MSV from CW to GCW shall be capable of traversing a dry hard surface side slope up to and including 30 percent. Side slope operation shall be performed with either side of the vehicle facing up slope and without loss of stability or malfunction

79 Soft Soil Mobility equal to or greater than FCS

Derived from ORD lines 308 - 309

The Mobility Rating Speed (MSR) and the Percent Go/No Go in soft soil for the MSV must be equal to or greater than the FCS vehicle. Therefore, the trailer should provide equal performance. We need to determine what the FCS requirement is.

x Soft Soil Traversing Characteristics. The FTTS-MSV (with companion trailer) shall have equal or better Mobility Rating Speed (MRS) and percent GO/NO-GO than the FCS.

80 Central Tire Inflation System (CTIS)

ORD lines 329 - 337

The requirement is to be able to adjust the MSV/trailer tire pressures to improve cross country mobility. The range of parameters that must be considered are GVW to GCW, axle locations, and terrain conditions.

xThe FTTS MSV and its companion trailer shall incorporate means to adjust tire pressure to increase cross country mobility. The FTTS-MSV shall incorporate this capability to allow the operator to adjust tire pressure.

81 FTTS will have variable height

Program charts

109.62 inches raised (24 inch ground clearance) and 94.62 inches squatted (9 inch ground clearance). FTTS is 374.5 inches long and has a 96 inch width, with a 77 inch track? Note that these dimensions are subject to change.

xDimensions do not apply to the companion trailer, these are dimensions and requirements for the FTTS prime mover. Variable height may however be required for the trailer to meet transport requirements.

POWERED TRAILER REQUIREMENTS TRACEABILITY/RATIONALE MATRIX (RTRM)

RTRM Sample Sheet(Transport & Trailer Requirements)

Statistics: - Number of Requirement Paragraphs: 135 - Number of Stated Requirements: 250 - Requirements Needing Clarification: 20 (8%) - Number of Requirement Disconnects: 12 (5%) Total Requirement Issues: 32 (13%)

RTRM Helps To Identify & Resolve Requirement Issues9INCOSE BRIEF @ DRS Technologies

• The N2 diagram illustrates interfaces and relationships between system requirements, parameters, and metrics

• System functions or elements are listed in the diagonal boxes

• Interfaces and relationships are identified in the off-diagonal boxes. Data flows in a clockwise direction between functions or elements

The next example illustrates a modified form of N2 where requirements have been listed in the diagonal boxes

System N2 Diagram

Helps To Surface Interface IssuesN2 Helps To Identify Interface Issues


Example N2 DiagramMobility Payload Protection Transportability C4ISR/EW Elec

PowerSupportability GVW Curb

WeightHeight

Mobility %NO-GO <25 45-50

mph on 5% Grade

Payload: GVW-CW-Crew

24” Ground Clearance Desired

Turning Radius of 25’ SA (FBCB2, MTS)

Engine Gen/

Alternator

Fuel SpecificsDiesel 80 gm/kWh

JP8 88 gm/kWh

Pwr to Weight Ratio

>30 bhp/ton

See GVW t/2h ≥ 1.20 for Stability

Payload Suspension Max Payload at 5100

lbs

Weight Trades Essential Combat Configuration (ECC)

C2 EquipMed Equip

Weight Trades

Sustainment Supplies for 3

Days

Weight Trades

Payload to Curb

Weight Ratio ≥

0.5

H=76” for MPF 102”

C-130

Protection Protection for Crew Vs.

Weight

KE, MINE, IED, Overhead

Ease of B-Kit Armor R/R

Threat Types & Locations

Active Armor

Protection

Armor Repair Costs

Weight Trades

Integral Armor

GPK, CROWS,

Weapons

Transportability (2) C-130,CH-47, CH-53, MPF

Operator Remote Control

Climbing Ramps

Trailers 18,000 lbs (2) On C-130

12,000 lbs Desired

H=76” for MPF 102”

C-130

C4ISR/EW Obstacle Avoidance

Net-ready, C2, FBCB2, MTS

Silent Watch

(2 Hours)

RFID C2 Equip Weight

C2 Equipment Weight

Antennas

Elec Power Hybrid Drive Option

15 kW OB10 kW Exp

Exp Power Weight Trades

A-Kit Vs B-Kit

Supportability Fuel Efficiency

60 ton-mpg400 mile

range

StowageItems

BII

Health Mgt.CBM+

A0=95%MMBF=10,000for Production

GVW Acceleration 13,000 lbs Max.Axel Loading

Not Specified

GVW: CW + Payload

+ Crew

Height Impacts Weight

Curb Weight Weight Trades

Weight Trades 13,000 lbs Max.Axel Loading

Not Specified

Height Impacts Weight

Height Suspension < 157.5” for Berne

Tunnel

• Proven, effective means to deal with complex decision making involving multiple criteria

• Captures both subjective and objective evaluation measures• A hierarchal decomposition of requirements or goals is

accomplished• Pair wise comparisons of requirement attributes are made and

relative scores computed for each leaf of the hierarchy• Scores are then synthesized yielding the relative weights at each

leaf as well as for the overall model• A coherent assessment is reached when Inconsistency Ratio < 0.1

(http://people.revoledu.com/kardi/tutorial/AHP/Consistency.htm)

Analytical Hierarchy Process (AHP)

AHP Helps to Determine Relative Importance


ModelLevel 1

Mobility Transportability Survivability C4IRS/EWPower

ManagementSupportability Payload

ModelLevel 2

GVW Driver Vision Stability Speed HP/ton Operational

Range

CW Height 76in Axle Loading 30 min Ready

CREW2.1 SD Weapon CBRNE Signature Mgt Ballistics

Protection

C3 SA Net

Security Bus

Architect

Power Buses OB Power Export Power Electrical

Storage

RAM Health Mgt HFE O&S Cost Commonality

Flatrack (3,200 lb)

Cargo (22,000 lb)

ModelLevel 3

Fuel efficiency (ton-mpg)

Fuel Capacity Armor

Protection

LVOSS Visual

signature Thermal

signature EM signature Direct Fire IED Mine Anti-tank Blast

Protection Seats

Crush resistant roof

ModelLevel 4

Fuel Specifics

ECU Map

Legend: GWV =Gross Vehicle Weight, CW = Curb Weight, C3 = Command, Control, Communications, SD = Self-Defense, SA = Situational Awareness, OB = On-Board, DVE = Driver Vision Enhancer, CBRNE = Chemical, Biological, Radiological, Nuclear Effects, IED =Improvised Explosive Device, LVOSS = Light Vehicle Obscuration Smoke System, LCC = Life Cycle Cost, UPC = Unit Production Cost

Requirements Model Breakdown


Combinatorial Trade Study- Requirements ImportanceLevel 1 Requirements – Per Customer Attribute Weights (weights can be modified for tradeoff purposes)Mobility 0.14Payload 0.20Transportability 0.20Survivability 0.10C4ISR/EW 0.13Power Mgt 0.07Supportability 0.16Total 1.00

Notes: If Row and Column are of equal importance then 1; minimize use of 1If Row more important than Column then 2If Column more important than Row then 0Only need to assess White pairs; Gray pairs are diagonal or self-calculated

Level 2 Requirements- MobilityGVW Driver Vision Roll Stability Top Speed Hp/ton Operating Range Weighting Normalized Global

GVW 1 0 0 2 0 0 3 0.083 0.012Drive Vision 2 1 1 2 1 2 9 0.250 0.035Roll Stability 2 1 1 2 2 2 10 0.278 0.039Top Speed 0 0 0 1 0 0 1 0.028 0.004Hp/ton 2 1 0 2 1 1 7 0.194 0.027Operating Range 2 0 0 2 1 1 6 0.167 0.023

Totals 36 1 0.140Level 3 Requirements- Operating Range

Fuel Efficiency Fuel Capacity Armor Protection Weighting Normalized GlobalFuel Efficiency 1 0 2 3 0.333 0.0078Fuel Capacity 2 1 2 5 0.556 0.0130Armor Protection 0 0 1 1 0.111 0.0026

Totals 9 1.000 0.023Level 4 Requirements- Fuel Efficiency

Fuel Specifics ECU Map Weighting Normalized GlobalFuel Specifics 1 2 3 0.750 0.0058ECU Map 0 1 1 0.250 0.0019

Totals 4 1 0.0078

Analytical Hierarchy Process Snapshot


• There are many customers• There are stated and unstated requirements• QFD helps to prioritize requirements and their

tradeoffs• QFD makes invisible requirements and strategic

advantages visible• QFD helps to define which improvements provide

the most gain• QFD promotes Team Consensus• QFD provides a documented audit trail for decisions

Quality Function Deployment (QFD)

The “House of Quality” Captures the Voice of the Customer15INCOSE BRIEF @ DRS Technologies

“House of Quality”

Interrelationships between Technologies

Technologies (Voice of the Company)

Requirements/Desires (Voice of the Customer)

Planning Matrix -Requirements Importance -Percent Improvement Desired -Marketing Competition Assessment

Relationships between Requirements and Technologies

Prioritized Technologies


• Two meetings were conducted with shareholders to get consensus on the Powered Trailer “House of Quality”

• Body of Matrix– Common definition/scope for each requirement and

technical attribute agreed to– Reinforced relationship values - by convention:

• (0-none, 1-weak, 3-moderate, 9-strong)– Recognized the most important associations– Segregated positive and negative correlations,

ensured they were mutually exclusive– Achieved Consensus, Consensus, Consensus

• QFD was finalized via (2) additional WebEx conferences

Powered Trailer QFD Analysis


+-

+DIRECTION OF MOVEMENT ↑ ↓ ↑ - + ↑Technology Areas Propulsion Power Mgt & Control Remote Operations Suspension Axles Steering Braking Cargo Handling Survivability Storage Tech.Diagnostics/Prognostics PLANNING MATRIX

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Ste

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Requirements PERFORMANCEMaximize payload 4 1 1 3 9 1 9 3 1 4 1.00 4 3.1Dash speed (deleted) 0 0.00 0 0Minimize turning radius 3 3 9 3 1.50 4.5 3.5Step up vertical obstacle 2 3 3 9 3 2 1.50 3 2.3Fording 4 1 1 3 4 1.15 4.6 3.6Cross trenches 3 3 3 9 9 3 1.30 3.9 360% longitudinal slope 4 9 9 9 4 1.25 5 3.930% side slope 4 9 9 4 1.00 4 3.1Transportability - via surface 5 3 3 5 1.50 7.5 5.8Transportability - via air 5 9 9 9 3 3 3 3 1 3 5 1.20 6 4.6No mobility degradation 5 9 9 9 9 9 1 9 9 3 5 2.00 10 7.7Range (fuel economy) 5 3 3 3 9 5 1.30 6.5 5Self-charging system 2 3 9 2 1.00 2 1.5Pwr & control from truck 3 1 1 3 3 9 9 3 9 3 3 1 3 1.25 3.8 2.9Trailer has own brakes 5 9 5 1.00 5 3.9Trailer provides export pwr 2 9 9 9 3 3 2 1.25 2.5 1.9Enhanced survivability 2 1 1 9 2 1.20 2.4 1.9Communicate with truck 5 9 9 9 9 9 5 1.30 6.5 5"FTTS" Prime Mover Interoperability5 9 3 9 9 3 3 3 3 3 3 3 3 1 1 3 9 5 1.00 5 3.9"Current" Prime Mover Interoperability3 9 3 3 1 3 1 1 1 3 1.10 3.3 2.6Interface with flatracks/cargo 5 9 9 9 9 5 1.25 6.3 4.8Auto self fuel 1 9 9 1 1.10 1.1 0.9O&S COST RELATEDMaintenance Ratio 0.025 5 9 3 3 1 1 1 1 9 1 9 3 3 9 9 1 1 1 5 1.40 7 5.4On-board fluid analysis 3 1 1 1 1 9 3 1.10 3.3 2.6Embedded diag/prognostics 5 1 1 1 9 9 9 5 1.20 6 4.6Fault isolation (deleted) 0 0.00 0 0Configuration Commonality 4 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 9 9 9 4 1.25 5 3.9Min.storage system maint. (deleted) 0 0.00 0 0Reliability 5 9 3 3 1 1 3 1 9 3 9 3 3 3 1 9 3 3 9 5 1.20 6 4.6ENVIRONMENTAL (Temp/EMI/Vib/Shock/Corrosion) 4 9 3 1 3 1 1 1 4 1.30 5.2 4

TECHNICAL DIFFICULTY(TD) 3 2 2 1 2 2 2 1 1 2 2 2 2 2 2 2 2 2 2 2 2 1 2 2 2 1 129 100TD Normalized 1.5 1.0 1.0 0.5 1.0 1.0 1.0 0.5 0.5 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 0.5 1.0 1.0 1.0 0.5COST FACTOR 3 2 2 1 2 2 2 2 1 2 2 1 2 2 2 1 1 2 2 2 1 2 3 2 2 1Cost Factor Normalized 1.5 1.0 1.0 0.5 1.0 1.0 1.0 1.0 0.5 1.0 1.0 0.5 1.0 1.0 1.0 0.5 0.5 1.0 1.0 1.0 0.5 1.0 1.5 1.0 1.0 0.5

TECHNOLOGY PRIORITIES 504 73 95 89 354 0 90 45 39 150 469 75 237 323 125 77 110 15 33 80 11 29 489 186 197 63 3959PERCENTAGE OF TOTAL 12.7 1.9 2.4 2.2 9.0 0.0 2.3 1.1 1.0 3.8 11.8 1.9 6.0 8.2 3.2 2.0 2.8 0.4 0.8 2.0 0.3 0.7 12.4 4.7 5.0 1.6 100

Powered Trailer “House of Quality”

Powered Trailer “House of Quality”

INCOSE BRIEF @ DRS Technologies 19

Trailer QFD

QFD Relative Ranking0

10

20

30

40

50

60

70

80

90

100 Suspension

ICE

Hybrid

Braking

Pwr Storage

Steering

Towed

LHS

Serial Bus

Auto ID

Adj. Deck

3 Axles

Umbilical

MIP

Elect PTO

Smart Tie

Mech PTO

Signature Mgt

Wireless

(Excludes Technical Difficulty and Cost Factors)

QFD Relative Ranking


• Combining individual preferences to form a group utility function presents a problem

• The use of averaged group preference data in product design optimization can lead to erroneous results

• This problem may not always be self-evident in the analysis of complex systems and products

Arrow’s Impossibility Theorem (A Word of Caution!)

Provides a Hierarchical Model For Doing TradeoffsGroup Consensus Must Be Reached To Avoid This Problem


• Designed for multi-dimensional, non-quantifiable problem complexes

• Explores boundary conditions• Investigates the total set of possible

relationships and “configuration” alternatives• Rules out alternatives that are inconsistent

or incompatible using cross-consistency assessment

Morphological Analysis

MA Ensures No Alternative is Overlooked


Morphological Field Example:

75 cells or configurations (Zwicky, 1969, p. 118.)

3-Parameters: color, texture, size

Color: 5 discrete values: red, green, blue, yellow, brown

Texture: 5 discrete values: smooth, serrated, rough, grainy, bumpy

Size: 3 discrete values: large, medium, small


MA-Trailer Drive AlternativesNo.

Vehicle Output

Energy Form

Trailer Drive Consistency? YES/NO

1 Mechanical Mechanical YES

2 Mechanical Electrical NO

3 Mechanical Hydraulic NO

4 Mechanical ICE NO

5 Electrical Mechanical NO

6 Electrical Electrical YES

7 Electrical Hydraulic NO

8 Electrical ICE NO

9 Hydraulic Mechanical NO

10 Hydraulic Electrical NO

11 Hydraulic Hydraulic NO

12 Hydraulic ICE NO

13 None Mechanical NO

14 None Electrical NO

15 None Hydraulic NO

16 None ICE YES

17 None Hybrid Electric YES

18 None Hybrid Hydraulic

YES

(5) Drive Alternatives Remain in Trade Space

Vehicle Output Energy Form

Trailer Drive Type

Mechanical Mechanical

Electrical Electrical

Hydraulic Hydraulic

None Internal Combustion Engine (ICE)

Hybrid Electric

Hybrid Hydraulic


Number of Configurations or Alternatives 4 X 6 = 24

Ruled out Combinations of Output Energy and Hybrid 3 X 2 = 06

18 Alternatives to Investigate→

• ALT #1 Electric PTO -Electrical Power Take Off provided by the transport

• ALT #2 HEV -Series Hybrid Electric Vehicle with ICE, generator, and battery pack

• ALT #3 HHV -Hybrid Hydraulic Vehicle with hydraulic power provided by an ICE driven power pack

• ALT #4 Mechanical PTO -Mechanical Power Take Off provided by the transport

• ALT #5 ICE Drive -ICE (210 HP with 340 ft-lb torque) with conventional drive train

Powered Trailer Design Concepts

ICE = Internal Combustion Engine


• 395/85 R20 XZL tires• Central Tire Inflation System (CTIS)• Pneumatic Anti-Lock Brake System (ABS)• Serial communications with transport

– Control of mobility assist and CTIS– Receipt of trailer health and cargo load

status• Independent Suspension• Trailer bed basic design

Features Common To All Concepts


Transport

Battery Pack 36 kW-hr(25) 120 amp-hr batteries motor

motor

Control box/Inverter

Control box/InverterDisplay

TrailerS

tee

rin

ga

ctu

ato

r

System Controller DC-AC Inverter

Air

tan

ks

CT

IS

ABS

pump

radiator

Operator RemoteControl Unit

Export Power

Note: Brake and CTIS lines not shown for clarity

mechanical

200 Kw 300 vdc

12/24 vdcfor electronics,trailer lights, etc.

pneumatic

discrete

serial

ALT #1 Elect PTO

Transport

Battery Pack 36 kW-hr(25) 120 amp-hr batteries

motormotor Control box/Inverter

Control box/InverterDisplay

Trailer

Ste

erin

gac

tua

tor

System Controller DC-AC Inverter

Air

tank

s

CT

IS

ABS

pump

radiator


Export Power

Note: Brake and CTIS lines not shown for clarity

mechanical

12/24 vdcfor electronics,trailer lights, etc.

pneumatic

discrete

serial GeneratorICE

fue

ltan

k

ALT #2 HEV

ALT #3 HHV

Display

Transport

Trailer

mechanical

12/24 vdc

pneumatic

discrete

serial

System Controller


Display

for electronics,trailer lights,etc.

ABS

Note: Brake and CTISlines to wheels not shownfor clarity

Pump/motor

High pressure accumulator

Low pressurereservoir

hydraulic

ICE

ALT #4 Mech PTO

Display

Transport

Trailer

mechanical

12/24 vdc

pneumatic

discrete

serial

System Controller Display


ABS


PTO

ALT #5 ICE Drive

Display

Transport

Trailer

mechanical

12/24 vdc

pneumatic

discrete

serial

DC-AC Inverter

Export Power

System Controller


Display


ABS


ICEGenerator CVT

FuelTank

Architectural Views for all Five Alternatives

Concepts


ALT#1 Electric

PTO

ALT#2 HEV

ALT#3 HHV

ALT#4 Mech PTO

ALT#5 ICE drive

Wheel Drive 4 x 2 4 x 4 4 x 2 4 x 2 4 x 4

Suspension Double A-Arm Double A-Arm Trailing Arm Either Type Either Type

Length (in) Width (in) Deck Height (in) Ground Clearance (in)

280 96

51.5

18

328 96

51.5

18

285 96

51.5

18

280 96

51.5

18

328 96

51.5

18 Track (in) 81 81 79 81 81

Wheel Base (in) 192 192 201 192 192 Basic Bed (lbs)

5,745 5,745 5,745 5,745 5,745

Suspension & Power Drive (lbs)

6,625 9,800 5,155 4,875 7,570

Flat rack (lbs)

3,200 3,200 3,200 3,200 3,200

Cargo Load (lbs)

22,000 22,000 22,000 22,000 22,000

Total Weigh-lbs

37,570 18.8 ST

40,395 20.2 ST

36,100 18.1 ST

35,820 18 ST

38,515 19.3 ST

ST = Short Ton or 2,000 lbs

Physical Characteristics


ALT #1 Elect PTO Components

Detail Needed for Credible Cost & Schedule Estimates29INCOSE BRIEF @ DRS Technologies

Cost Vs Key Requirements Met

$35K

$40K

$55K

$70K

$140K

$150K

0 10 20 30 40 50 60 70 80 90 100

Basic 45

Mech PTO 60

Elec PTO 75

ICE 85

HEV 95

HHV 85

Cost Vs Key Requirements Met

Percent of Key Requirements Met

Co

stp

er 1

000

Un

its


Trade Parameters

Requirement

Weightings

Alt #1Elect PTO

Alt #2HEV

Alt #3HHV

Alt #4Mech PTO

Alt #5ICE

Drive

Mobility Assist 5 | 5 3 5 4 3 5

Self Mobility 3 | 3 0 5 4 0 4

Payload 4 | 4 5 4 4 5 4

Complexity (RAM)

2 | 4 4 2 2 5 3

Interoperability

4 | 4 3 4 1 2 4

Maturity 2 | 4 4 3 2 5 5

Commonality 3 | 2 4 4 1 1 2

Unit Prod Cost 4 | 4 4 1 1 5 3

Weighted Score

91 |103 98 |104 67 | 74 86 |105 103 |117

Normalized Score

1.36 |1.39 1.46 |1.41 1 | 1 1.28 |1.42 1.54 |1.58

Comparison of Alternatives

Weighting/Scoring 0-5 with 5 Best


• Understanding requirements; their relationships, and relative importance:– Tools: RTRM, N2 Diagram, AHP

• Getting consensus on the best technology options for meeting customer needs:– Tools: QFD (House of Quality)

• Evaluating alternatives:– Tools: AHP, MA, Architectural Views

• Selecting the best alternative:– Tools: Trade Study, Sensitivity Analysis

SE Tool Usage Summary


• SE Process Critical for Providing Best Balanced Solution

• SE Tools Assist in:– Understanding requirements and their relationships– Getting consensus on which technology options provide

the greatest benefits– Assuring no viable alternative is overlooked– Performing meaningful tradeoffs and sensitivity analysis– Making decisions involving multiple attribute criteria

Conclusions

Capturing the Results in the Requirements Set Reduces Program Execution Risks

Go to: www.incose.org for more information


http://www.incose.org/

Questions ?


Documents

“A Systems Engineering Approach For Balancing Powered Trailer Requirements” Dana Peterson (CSEP Acq) [email protected] (314) 553-4599