“A Systems Engineering Approach For Balancing Powered Trailer Requirements” - PowerPoint Presentation

Slide1

“A Systems Engineering Approach For Balancing Powered Trailer Requirements”

Dana Peterson (CSEP Acq)

dpeterson@drs-ssi.com

(314) 553-4599

Slide2

Illustrate a sample of Systems Engineering tools used on the Powered Trailer project to:Resolve requirement issuesUnderstand relationships between requirementsPrioritize requirements

Get consensus on the best technology optionsProvide the best “balanced” overall solution

Purpose of Presentation

2

INCOSE BRIEF @ DRS Technologies

Slide3

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

3

INCOSE BRIEF @ DRS Technologies

Slide4

Requirements Traceability/ Rationale Matrix (RTRM)

N2

Diagram

Analytic Hierarchy Process (AHP)

Quality Function Deployment (QFD)

Morphological Analysis (MA)Architecture Views

Trade StudySensitivity Analysis

Affinity DiagramTree DiagramFishbone Diagram

Digraph

Blueprinting

Arrow Diagram

Matrix Diagram

Relations Diagram

Process Decision Program Chart

Flow Diagram

Context Diagram

Pugh Matrix

Specification

Sample SE Tools

4

INCOSE BRIEF @ DRS Technologies

Slide5

Systems Engineering Approach

Performance

Spec

User

Requirements

Requirements

Traceability/Rationale Matrix

(RTRM)

Requirement

Prioritization

QFD

House

Of Quality

Power Trailer

Design Alternatives

Mobility

Analysis

Trade Studies

-Performance

-Payload

-C-130 Transport

-R&M

-Cost

-Schedule

Technology

Options

Sensitivity

Analysis

Preferred

Solution

AHP

MA

Legend

AHP = Analytical Hierarchy Process

QFD = Quality Function Deployment

MA = Morphological Analysis

An Iterative Hierarchical Process That Provides the Best

Overall Requirements Balance

Slide6

Many requirements in diverse functional areasA lot of stakeholders involved

Tools are needed to balance requirements and validate concept prior to project executionCost and schedule are receiving a lot more attention

Multi-Attribute Criteria Problem

Performance

Cost

Schedule

6

INCOSE BRIEF @ DRS Technologies

Slide7

Solution Synthesis is Becoming More Challenging

Design for Adaptability

Performance

Cost

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 Design

Security

7

INCOSE BRIEF @ DRS Technologies

Slide8

Prioritizing Requirements:Spiral 1, 2, 3 Evolution

Threshold Vs ObjectiveKey Performance Parameters Vs Key System Attributes Vs Additional Attributes

Tier Levels 1, 2, 3, 4Asking:

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!

8

INCOSE BRIEF @ DRS Technologies

Slide9

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 Issues

9

INCOSE BRIEF @ DRS Technologies

Slide10

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 N

2 Diagram

Helps To Surface Interface Issues

N

2

Helps To Identify Interface Issues

10

INCOSE BRIEF @ DRS Technologies

Slide11

Example N2 Diagram

Mobility

Payload

Protection

Transportability

C4ISR/EW

Elec

Power

Supportability

GVW

Curb

Weight

Height

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 Specifics

Diesel

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 Equip

Med

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

OB

10 kW Exp

Exp Power

Weight Trades

A-Kit

Vs

B-Kit

Supportability

Fuel Efficiency

60

ton-mpg

400 mile range

Stowage

Items

BII

Health Mgt.

CBM

+

A

0

=95%

MMBF=10,000

for 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

Slide12

Proven, effective means to deal with complex decision making involving multiple criteriaCaptures both subjective and objective evaluation measures

A hierarchal decomposition of requirements or goals is accomplishedPair 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

12

INCOSE BRIEF @ DRS Technologies

Slide13

Model

Level 1

Mobility

Transportability

Survivability

C4IRS/EW

Power

Management

Supportability

Payload

Model

Level 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)

Model

Level 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

Model

Level 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

13

INCOSE BRIEF @ DRS Technologies

Slide14

Combinatorial Trade Study- Requirements Importance

Level 1 Requirements

– Per Customer Attribute Weights (weights can be modified for tradeoff purposes)

Mobility

0.14

Payload

0.20

Transportability

0.20

Survivability

0.10

C4ISR/EW

0.13

Power Mgt

0.07

Supportability

0.16

Total

1.00

Notes:

If Row and Column

are of equal importance then 1; minimize use of 1

If Row

more important than Column then 2

If Column more important than Row then 0

Only need to assess White pairs; Gray pairs are diagonal

or self-calculated

Level 2 Requirements-

Mobility

GVW

Drive

r Vision

Roll Stability

Top Speed

Hp/ton

Operating Range

Weighting

Normalized

Global

GVW

1

0

0

2

0

0

3

0.083

0.012

Drive Vision

2

1

1

2

1

2

9

0.250

0.035

Roll Stability

2

1

1

2

2

2

10

0.278

0.039

Top

Speed

0

0

0

1

0

0

1

0.028

0.004

Hp/ton

2

1

0

2

1

1

7

0.194

0.027

Operating

Range

2

0

0

2

1

1

6

0.167

0.023

Totals

36

1

0.140

Level 3 Requirements

- Operating Range

Fuel Efficiency

Fuel Capacity

Armor

Protection

Weighting

Normalized

Global

Fuel Efficiency

1

0

2

3

0.333

0.0078

Fuel

Capacity

2

1

2

5

0.556

0.0130

Armor

Protection

0

0

1

1

0.111

0.0026

Totals

9

1.000

0.023

Level 4 Requirements-

Fuel Efficiency

Fuel Specifics

ECU Map

Weighting

Normalized

Global

Fuel Specifics

1

2

3

0.750

0.0058

ECU Map

0

1

1

0.250

0.0019

Totals

4

1

0.0078

Analytical Hierarchy Process Snapshot

14

INCOSE BRIEF @ DRS Technologies

Slide15

There are many customersThere are stated and unstated requirements

QFD helps to prioritize requirements and their tradeoffsQFD makes invisible requirements and strategic advantages visibleQFD 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 Customer

15

INCOSE BRIEF @ DRS Technologies

Slide16

“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

16

INCOSE BRIEF @ DRS Technologies

Slide17

Two meetings were conducted with shareholders to get consensus on the Powered Trailer “House of Quality”Body of MatrixCommon 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 associationsSegregated positive and negative correlations, ensured they were mutually exclusive

Achieved Consensus, Consensus, ConsensusQFD was finalized via (2) additional WebEx conferences

Powered Trailer QFD Analysis

17

INCOSE BRIEF @ DRS Technologies

Slide18

Powered Trailer “House of Quality”

Slide19

Powered Trailer “House of Quality”INCOSE BRIEF @ DRS Technologies

19

Slide20

(Excludes Technical Difficulty and Cost Factors)

QFD Relative Ranking

20

INCOSE BRIEF @ DRS Technologies

Slide21

Combining individual preferences to form a group utility function presents a problemThe 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 Tradeoffs

Group Consensus Must Be Reached To Avoid This Problem

21

INCOSE BRIEF @ DRS Technologies

Slide22

Designed for multi-dimensional, non-quantifiable problem complexesExplores boundary conditionsInvestigates 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

22

INCOSE BRIEF @ DRS Technologies

Slide23

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, bumpySize: 3 discrete values: large, medium, small

23

INCOSE BRIEF @ DRS Technologies

Slide24

MA-Trailer Drive Alternatives

No.

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

24

INCOSE BRIEF @ DRS Technologies

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

→

Slide25

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

ALT #2 HEV -Series Hybrid Electric Vehicle with ICE, generator, and battery packALT #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 Engine25

INCOSE BRIEF @ DRS Technologies

Slide26

395/85 R20 XZL tiresCentral Tire Inflation System (CTIS)Pneumatic Anti-Lock Brake System (ABS)

Serial communications with transportControl of mobility assist and CTISReceipt of trailer health and cargo load status

Independent Suspension

Trailer bed basic design

Features Common To All Concepts

26

INCOSE BRIEF @ DRS Technologies

Slide27

ALT #1 Elect PTO

ALT #2 HEV

ALT #3 HHV

ALT #4 Mech PTO

ALT #5 ICE Drive

Architectural Views for

all Five Alternatives

Concepts

27

INCOSE BRIEF @ DRS Technologies

Slide28

Physical Characteristics

28

INCOSE BRIEF @ DRS Technologies

Slide29

ALT #1 Elect PTO Components

Detail Needed for Credible Cost & Schedule Estimates

29

INCOSE BRIEF @ DRS Technologies

Slide30

Cost Vs Key Requirements Met

30

INCOSE BRIEF @ DRS Technologies

Slide31

Trade Parameters

Requirement

Weightings

Alt #1

Elect PTO

Alt #2

HEV

Alt #3

HHV

Alt #4

Mech PTO

Alt #5

ICE

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

31

INCOSE BRIEF @ DRS Technologies

Slide32

Understanding requirements; their relationships, and relative importance:Tools: RTRM, N2 Diagram, AHPGetting 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

32

INCOSE BRIEF @ DRS Technologies

Slide33

SE Process Critical for Providing Best Balanced SolutionSE Tools Assist in:Understanding requirements and their relationships

Getting consensus on which technology options provide the greatest benefitsAssuring no viable alternative is overlooked

Performing meaningful tradeoffs and sensitivity analysisMaking 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

33

INCOSE BRIEF @ DRS Technologies

Slide34

Questions ?

34

INCOSE BRIEF @ DRS Technologies