Chap 10 Managing Engineering Design. Advanced Organizer

Chap 10 Managing Engineering Design

D ecision Mak ing

P lanning

O rganizing

Leading

C ontro lling

Managem ent Functions

R esearch

D esign

Production

Q uality

Marketing

Project Managem ent

Managing Technology

Tim e Managem ent

E thics

C areer

Personal Technology

Managing Engineering and Technology

Advanced Organizer

Chapter Objectives

Describe the phases or stages in systems engineering and the new product development processRecognize product liability and safety issuesRecognize the significance of reliability and other design factors

Nature of Engineering Design

Eng. Design Process

Information: •Statement of the problem•Design standards•Design methods

Information: •Drawings•Specifications•Financial estimates•Written reports•Oral presentations

SYSTEMS ENGINEERING/

NEW PRODUCT DEVELOPMENT

The design of a complex engineered system, from the realization of a need through production to engineering support in use is known as systems engineering (especially with military or space systems) or as new product development (with commercial systems).

New Product Development - Stages

Conceptual Technical Feasibility or Concept DefinitionDevelopmentCommercial ValidationProductionProduct SupportDisposal Stage

Systems Engineering Process(In each phase of development)

Requirements Analysis: Analyze customer needs, objectives, and constraints to determine the functional requirements.Functional Analysis/Allocation Identify lower level functions needed to meet these functional requirements, and translate them into design requirements suitable as design criteria.Synthesis. Define the system concept, configuration item alternatives and select the preferred set of product or process solutions to the level of detail required in the phase being conducted.

Systems Engineering Process(In each phase of development)

System Analysis and Control. Provide the progress measurement, assessment, and decision mechanisms required to evaluate design capabilities and document the design and decision data. – Trade-off (trade) studies– Risk management– Configuration management– Interface management – Systems engineering master schedule (SEMS) – Technical performance measurement (TPM) – Technical (design) reviews

Quality Function Deployment (QFD)Quality function deployment is a team-based management tool in which the customer expectations are used to drive the product development process. Conflicting characteristics or requirements are identified early in the QFD process and can be resolved before production.

Quality Function Deployment (QFD)Key benefits:

product improvement, increased customer satisfaction,reduction in the total product development cycle, &increased market share.

Quality Function Deployment (QFD)Identify User Needs & Wants

Gather raw data– Interviews– Focus Groups– Observation

Interpret raw data– Affinity Diagram– Needs Statements

Organize needs & establish importance – Surveys– Conjoint Analysis

Quality Function Deployment (QFD)

Identify User Needs & WantsGather raw data (Interview Segmentation)

UnhappyCustomers

HappyCustomers

Never TriedProduct

PreferCompetitors

LeadUsers

Male

Female

Children

Tra

dit

ion

al D

em

ogra

ph

ic

Segm

en

tati

on

Non-Traditional Segmentation


Gather raw data (How many interviews are needed? )

Number of Custom ers Interview ed

0%

20%

40%

60%

80%

100%

5 10 15 20 25 30

Percent of NeedsIdentified

G riffin & H auser 1993


Gather raw data (Focus Groups)

From: Griffin, Abbie and John R. Hauser. “The Voice of the Customer”, Marketing Science. vol. 12, no. 1, Winter 1993.

One-on-One Interviews (1 hour)

Focus Groups (2 hours)

0 1 2 3 4 5 6 7 8 9 10

0

20

40

60

80

100

Per

cen

t o

f N

eed

s Id

enti

fied

Number of Respondents or Groups


Interpret raw data– Affinity Diagram

Organizes subjective information Example: Group the following CR’s

• “ease of handling”• “portability” • “number readability” • “load handling”• “ease of use”

Quality Function Deployment (QFD)

Identify User Needs & WantsInterpret raw data (Needs Statements)– What, not How– Be specific– Positive, not negative– Attributes of the product– Avoid “must” or “should”.

House of Quality

Interrelationshipbetween

Technical Descriptors

Technical Descriptors(Voice of the Organization)

Relationship betweenRequirements and Descriptors

Prioritized Technical Descriptors

Pri

oriti

zed

Cus

tom

er

Req

uire

men

ts

Cus

tom

er

Req

uire

men

ts (Voi

ce o

f th

e C

usto

mer

)Interrelationship

betweenTechnical Descriptors

Technical Descriptors(Voice of the Organization)

Relationship betweenRequirements and Descriptors

Prioritized Technical Descriptors

Pri

oriti

zed

Cus

tom

er

Req

mts

Cus

tom

er

Req

mts

(Voi

ce o

f th

e C

usto

mer

)

4 Phases of QFD

Classical Model of QFDMatrix What How

House of Quality

Voice of Customer

Tech. Performance

Measures

Subsystem Design Matrix

Tech. Performance

Measures

Piece/Part Characteristics

Piece/Part Design Matrix

Piece/Part Characteristics

Process Parameters

Process Design Matrix

Process Parameters

Production Operations

Customer Needs •Good image•Easy to transport•Keeps present. flowing•Image visible in bad conditions•Minimizes unplanned interruptions•Design makes the product attractive•Device sets up quickly•Works well for short present.

PHASE I QFD -- Portable Slide ProjectorEngineering Metrics

Customer Requirements Cu

sto

mer

Weig

hts

Bri

gh

tness

Weig

ht

Dim

en

sion

s (g

irth

+ w

idth

)

Tim

e/T

ask

s re

qu

ired

to s

tart

pre

sen

tati

on

Dis

tort

ion

Dis

tan

ce f

rom

pre

sen

ter

(wit

h 3

' x 3

' p

roje

cti

on

)

Tim

e t

o i

nse

rt/p

ull

-ou

t sl

ide

Att

racti

ve p

rod

uct

Good image 9 9 9Easy to transport 9 9 9Device sets up quickly 9 3 1 9 3 3Works well for short present. 9 1 3 3 3Keeps present. flowing 1 3 3 9Image visible in bad conditions 3 9 3Minimizes unplanned interruptions 1 3 1 9Design makes the product attractive 3 3 3 9

Raw score

10

8

11

7

10

8

11

4

90

58

72

27

Relative Weight 1

6%

17

%

16

%

16

%

13

%

8%

10

%

4%

Engineering Metrics•Brightness•Weight•Dimensions (girth + width)•Time/Tasks required to start present.•Distortion•Distance from presenter •Time to insert/pull-out slide•Attractive product

Portable Slide Projector

Example

QFD Matrix Example

Engineering Metrics

Customer Requirements Cus

tom

er W

eigh

ts

Brig

htne

ss

Wei

ght

Dim

ension

s (g

irth

+ w

idth

)

Tim

e/Tas

ks req

uire

d to

sta

rt p

rese

ntat

ion

Disto

rtio

n

Dista

nce

from

pre

sent

er (w

ith

3' x

3' p

roje

ctio

n)

Tim

e to

inse

rt/p

ull-ou

t slid

e

Attra

ctiv

e pr

oduc

t

Good image 9 9 9Easy to transport 9 9 9Device sets up quickly 9 3 1 9 3 3Works well for short present. 9 1 3 3 3Keeps present. flowing 1 3 3 9Image visible in bad conditions 3 9Minimizes unplanned interruptions 1 3 1 9Design makes the product attractive 3 3 3 9

Raw score

108

117

108

114

81 58 72 27

Relative Weight 16

%

17%

16%

17%

12%

8% 11%

4%

Phase I -


Part Characteristics

Engineering Metrics Ph

ase

I R

ela

tive

Weig

hts

Top c

ase

Bott

om

case

Lens

Condense

rS

tand

Heat

sink

Lam

p

Brightness 16% 9 9 1 9Weight 17% 9 9 1 1 3Dimensions (girth + width) 16% 9 9 3 9 1 3 3Time/ Tasks required to start presentation 16% 3 3Distortion 13% 9 9 1 1Distance from presenter (with 3' x 3' projection) 8% 9 9 9Time to insert/ pull-out slide 10% 3 1Attractive product 4% 9 9 9

Raw score 3

.6

3.3

4.4

4.9

1.1

1.3

2.7

Rel. Weight 1

7%

15%

21%

23%

5%

6%

13%

Rank 3 4 2 1 7 6 5

Phase II -


Phases in Systems Engineering / New Product Development

(DoD)

Pre-milestone zero studiesConcept exploration & definitionDemonstration and validationEngineering and manufacturing developmentProduction and deploymentOperations and support


(NASA)

Conceptual design studiesConcept definitionDesign and developmentFabrication, integration, test, and certificationPre-operationsOperations and disposal


(NSPE/NIST )ConceptualTechnical feasibilityDevelopmentCommercial validation and production preparationFull-scale productionProduct support

Approval to expend the resources / agreement on the work to be accomplished. Accomplishment of the work Compile the results: designs and specifications, analyses and reports, and a proposed plan for conducting the following phase if one is recommended. – To cancel the development, – To go back (recycle) and do more work in the

present phase; or – To proceed with the next phase.

Tasks Within Each Phases of Systems Eng.

/New Product Development

Conceptual stage

Statement of the design problem, clearly defining what the desired intended accomplishment of the desired productKey functions Performance characteristicsConstraints Criteria of judging the design quality

Conceptual stage

Musts: requirements that must be metMust nots: constraints defining what the system must not be or doWants: features that would significantly enhance the value of the solution but are not mandatory (to which an additional, even less compelling category of "nice to have" is often added)Don't wants: characteristics that reduce the value of the solution

Conceptual stage(Kano’s Model)

Actual Performanc

e

Customer Satisfaction

Satisfiers

Dissatisfiers

Delighters

Conceptual stage (Kano’s

Model) Expected Quality Dissatisfiers

Smooth Surface Scratches, blemishes

All parts work Broken parts

Clear instruction Missing instruction

Normal function Function not provided

Product is safe to use Product is unsafe

Product conforms to std.

Product is non-conformant


Model)

Desired Quality

Performance Measure

Direction

Capacity Cubic feet of storage

LargerTB

Price Dollars SmallerTB

Reliability MTBF LargerTB

Speed Transactions /second

LargerTB

Satisfiers:


Model)

Examples of Delighters•Sony Walkman•3M Post-it•Cup Holder•One-touch recording•Redial button on telephone•Graphic User Interface (GUI)

Results from Conceptual stage

A set of functional requirementsIdentification of the potential barriers to development, manufacturing, and marketing the proposed product.Test-of-principle model to reduce technical uncertaintiesOrder-of-magnitude economic analyses and Preliminary market surveys to reduce financial uncertainty.

Importance of Conceptual stage

1% of the cost of the product70 % of the life-cycle cost

Technical feasibility stage

The objectives of this stage are To confirm the target performance of the new product through experimentation and/or accepted engineering analysis and To ascertain that there are no technical or economic barriers to implementation

Technical feasibility stage Typical steps:

Subsystem identificationTrade-off studiesSystem integrationInterface definitionPreliminary breadboard-level testing Subsystem and system design requirements (reliability, safety, maintainability, and environmental impact).Development of preliminary test plans, production methods, maintenance and logistic concepts, and marketing plans.Preliminary estimation of the life-cycle cost of the system.Preparation of a proposal for the development stage

Importance of Technical feasibility stage

7% of the cost of the product85 % of the life-cycle cost

Development stage (Build-test-fix-retest

sequences)The objective of this stage is

To make the needed improvements in materials, designs and processes and To confirm that the product will perform as specified by constructing and testing engineering prototypes or pilot processes.

Commercial validation and Production preparation

stage The objective of this stage is to develop the

manufacturing techniques and establish test market validity of the new product. Selecting manufacturing procedures, production tools and technology, installation and start-up plans for the manufacturing process, and Selecting vendors for purchased materials, components, and subsystems.

Reproduction prototypes

Full-scale production stage Final design drawings, specifications, flow charts, and procedures are completed for manufacture and assembly of all components and subsystems of the product, as well as for the production facility.Quality control procedures and reliability standards are establishedContracts made with suppliersProcedures established for product distribution and support. Manufacturing facilities are constructedContinuous process improvement (kaizen)

Product support stage Technical manuals for product installation, operation, and maintenance Training programs for customer personnelTechnical supportsWarranty servicesRepair parts and replacement consumables must be manufactured and distributedNew procedures for operation and maintenanceImproved parts for retrofitNotification of product recall for safety reasons

Disposal stage

Every product causes waste during manufacture, while in use, and at the end of useful life that can create disposal problems. The time to begin asking, "how do we get rid of this" is in the early stages of product or process design.

CONCURRENT ENGINEERING AND CALS

Traditional Product Development

System Level DesignSubsystem DesignComponent DesignManufacturing Process Concept DevelopmentManufacturing Process DevelopmentDelivery DevelopmentService DevelopmentDelivery

Concurrent Processes

System Level Design

Subsystem Design

Component Design

Manufacturing Process Concept Development

Manufacturing Process Development

Delivery Development

Service Development

Delivery

Definition of Concurrent Engineering

A systematic approach to the integrated, concurrent design of products and their related processes, including manufacture and support.

This approach is intended to cause the developer, from the outset, to consider all elements of the product lifecycle from concept through disposal, including quality control, cost, scheduling, user requirements. (Inst. For Defense Analysis)

Advantages of Concurrent Engineering

The set of methods, techniques, and practices that:Cause significant consideration within the design phases of factors from later in the life cycle;Produce, along with the product design, the design of processes to be employed later in the life of the product;Facilitate the reduction of the time required to translate the design into distributed products; andEnhance the ability of products to satisfy users' expectations and needs.

CALS

"Computer Aided Logistics Support," then "Computer-aided Acquisition and Logistics Support," "Continuous Acquisition and Life-Cycle Support," (1993, DoD)"Commerce At Light Speed" (U.S. industry)

Purposes of CALS

To enable more effective generation, management, and use of digital data supporting the life cycle of a product through the use of international standards, business process change, and advanced technology application.

CALS

Electronic storage, transmission, and retrieval of digital data Between engineers representing the several design stages, Between organization functions such as marketing, design, manufacturing, and product support, and Between cooperating organizations such as customer and supplier.

Commercial standardsComputer Graphics Metafile (CGM) (ISO-8632): A standard means of representing line drawings in a device-independent way.Electronic Data Interchange for Administration, Commerce, and Transport (EDIFACT) (ISO 9735, ANSI X12): An international standard means for communicating commercial (trade) information.Initial Graphics Exchange Specification (IGES) (ANSI Y14.26M): A standard means of representing product data in a device-independent way.

CONTROL SYSTEMS IN DESIGN

Drawing/Design ReleaseConfiguration (Design Criteria) Management– Functional baseline (at end of conceptual stage)– Allocated baseline (at end of validation stage)– Product baseline (at end of development stage)

Design Review

PRODUCT LIABILITY & SAFETY

Caveat emptor (let the buyer beware)“Privity of contract” (Direct contractual relationship)1916, MacPherson v. Buick (No need for direct contract)Plaintiff must prove negligence1960, Hernington v. Bloomfield Motors, implied warranty1984, Greenman v. Yuba Power Product Strict LiabilityAbsolute liability: “A manufacturer could be held strictly liable for failure to warn of a product hazard, even if the hazard was scientifically unknowable at the time of the manufacture and sale of the product.”

Reducing Liability Include safety as a primary specification for product design. Use standard, proven materials and components. Subject the design to thorough analysis and testing.Employ a formal design review process in which safety is emphasized.Specify proven manufacturing methods.Assure an effective, independent quality control and inspection process.Be sure that there are warning labels on the product where necessary.

Reducing Liability

Supply clear and unambiguous instructions for installation and use.Establish a traceable system of distribution, with warranty cards, against the possibility of product recall.Institute an effective failure reporting and analysis system, with timely redesign and retrofit as appropriate.Document all product safety precautions, actions, and decisions through the product life cycle.

DESIGNING FOR RELIABILITY

Definition of Reliability:Reliability is the probability that a systemWill demonstrate specified performance

For a stated period of time

When operated under specified conditions.

Reliability Measures

Reliability R(t)=St /S0

Failure CDF (cumulative distribution function): F(t)=0

t F / S0

Failure PDF (probability density function): f(t) = Ft /S0

Failure or hazard rate: (t)= Ft /St

Simple Reliability Models

Series modelParallel modelSeries- parallel modelBathtub curve

Designing for Reliability

“Start with the best”RedundancyFactor of safety

Maintainability

Maintainability is the probability that a failed systemWill be restored to specified performance

Within a stated period of time

When maintained under specified conditions.

Maintainability

Maintenance downtimeAdministrative & preparation timeLogistic timeActive maintenance time

Types of Maintenance Corrective maintenancePreventive maintenancePredictive maintenance

Availability

Inherent Availability (considers only corrective maintenance)Ai = MTBF / (MTBF+MTTR)Operational Availability (considers both preventive & corrective maintenance)Ao = MTBM / (MTBM+MDT)

MTBM: Mean Time Between MaintenanceMDT: Mean Down TimeMTTR: Mean Time To RepairMTBF: Mean Time Between Failure (1/)BIT: Build-In Test

Other Considerations

Human Factors Engineering (Ergonomics)Standardization– Set of specifications for parts, materials, or

processes intended to achieve uniformity, efficiency, and a specified quality.

Producibility

Value Engineering A methodical study of all components of a product in order

to discover and eliminate unnecessary costs over the product life cycle without interfering with the effectiveness of the product.

• What is it?• What does it do?• What does it cost?• What does it worth?• What else might do the job?• What do the alternatives cost?• Which alternative is least expensive?• Will the alternative meet the requirements?• What is needed to implement the alternative?

Documents

Chap 10 Managing Engineering Design. Advanced Organizer