EngineeringManagement

Systems EngineeringManagement

MSE607BChapter 5

Design Review and Evaluation

2

Learning Objectives

Explain the basic philosophy of design evolution Describe the evaluation methods Explain the informal and formal design reviews Explain the feedback and corrective-action loop

associated with these activities

3

Design Review and Evaluation

4

Design Review and Evaluation Requirements

Formal mechanism to ensure design will meet consumer need Design evolves through iterations from initial definition to firm

system configuration Requirements verification process required from the beginning

• Early detection of potential problems allows to incorporate necessary changes easily

• An ongoing design review and evaluation effort is required Overall review process through combination of several approaches:

• Informal day-to-day review and evaluation • Formal design reviews at designated stages

Serve as a vehicle for communications Serve as the formal approval of design data

5

Design Review and Evaluation Procedure

6

Informal Day-to-day Review and Evaluation

Performed as design decisions are made and data developed

Informal activity • Results of design reviewed and discussed on a day-by-day basis

Output leads into the formal design reviews

Ensure that the results of design:• Communicated in a clear, effective, and

timely manner to all members of the design team

• Compatible with initially defined requirements for the system

Review procedure has to be accomplished efficiently and in timely manner

7

Formal Design Reviews

Conducted at designated stages in the evolution of design

Serve as a vehicle for communications and the formal approval of design data.

Purpose• Review system requirements specification document• Ensure documented design reflect current knowledge of

customer and market requirements• Identify areas where design may not be consistent with

product development constraints• Put the design document under version control to serve

as a stable baseline for continued new product development

8

Formal Design Reviews (cont.)

Preliminary Design Review (PDR) • Ensure planned technical approach will meet the

requirements Critical Design Review (CDR)

• Ensure design implementation has met the requirements Test Readiness Review (TRR)

• Review preparations and readiness for testing, including test procedures

Production Readiness Review (PRR)• Ensure design completely and accurately documented• Ensure design ready for formal release to manufacturing

9

Conceptual (Preliminary) Design Review

PDR• Usually scheduled toward end of program conceptual

design• Deals primarily with top system-level requirements• Results constitute basis for preliminary system design

and development activity• Participation include representation from both the

consumer and producer organizationsPurpose:

• Review and evaluate the functional baseline of the system

10

Topics Covered in Conceptual Design Review

Objective• Review and evaluate functional baseline of the system

Feasibility analysis • Results of technology assessments and trade-off

studies justifying the system design approach being proposed

System operational requirements System maintenance concept

11

Topics Covered in Conceptual Design Review (cont.)

Functional analysis Significant design criteria for the system Effectiveness of merit and technical performance

measures System specification Type A System engineering management plan Test and evaluation master plan System design documentation

12

Systems Design Reviews

Usually scheduled during preliminary design phase• Functional requirements & allocations are defined• Preliminary design layouts & specifications are prepared• System-level trade-off studies are conducted

Oriented to the overall system configuration Ensure that requirements described in the system

specifications are maintained as design evolves Should include representation from

• Consumer• Producer• Major suppliers

13

Topics Covered in Systems Design Reviews

Functional analysis and the allocations of requirements Development, process, product, and material

specifications • Type B, C, D, and E

Design data defining the overall system Analysis, reports, trade-off studies, and related design

documentation. Assessment of proposed system design configuration in

terms of technical performance measures (TPMs) Individual program/design plans

14

Equipment/Software Design Reviews

Formal design reviews covering equipment, software, and other components of the system: • Scheduled during the detail design and development phase

of the life cycle• Usually oriented to a particular item• Should include representation from

• Consumer• Producer• Applicable supplier organizations

15

Topics Covered in Equipment/Software Design Reviews

Process, product, and material specifications • Types C, D, and E

Design data defining major subsystems, equipment, software, and other elements of the system as applicable

Analyses, reports, predictions, trade-off studies, and other related design documentation

Assessment of the proposed system design configuration in terms of the applicable TPMs

Engineering breadboards, laboratory models, service test models, mock-ups, and prototype models

Supplier data covering specific components of the system

16

Critical Design Review (CDR)

Generally scheduled after the completion of detail design, but prior to the release for production or construction • Design is essentially “frozen” at this point

Proposed configuration evaluated for adequacy and producibility

Results describe final system/product configuration baseline prior to entering into production or construction.

Constitute the last in series of progressive evaluation efforts• Reflecting design and development from a historical perspective• Showing growth and maturity in design as the engineering project

evolved

17

The Design Change and System Modification Process

Important that any changes to the baseline be tightly controlled

All changes carefully recorded and documented • Configuration identification• Controlling the changes• Maintaining the integrity and continuity of design• Configuration management

18

The Design Change and System Modification Process (cont.)

Configuration Management (CM)• Identifies the functional and physical characteristics of

an item• Controls changes to characteristics• Records and reports change processing and implementation

status

• Proposed design changes initiated during any phase in the life cycle

• Prepared in the form of an Engineering Change Proposal (ECP)

19

Engineering Change Proposal (ECP)

Each ECP should include:• Statement of the problem and description of proposed

change• Description of alternatives considered in responding to

the need• Analysis how change will impact system performance• Analysis to ensure proposed solution will not cause a

new problem • Preliminary plan for incorporating the change

20

Engineering Change Proposal (ECP) (cont.)

• Description of the resources required to implement the change

• Estimate of the costs associated with implementing the change

• Impact on the system if the proposed change is NOT implemented

Classified• Class 1 changes

• Design changes that will affect fit, form or function

• Class 2 changes • Design changes that are relatively minor in nature• Will not affect system specification requirements

• May be classified as “emergency”, “urgent,” or “routine”

21

Summary

Addressed the basic review, evaluation, and feedback process of system design

The process is critical in regard to the objectives of system engineering

Must be tailored to the specific system development effort and must be properly controlled

An ongoing measurement and evaluation activity is essential and must be initiated from the beginning

Without proper controls, the incorporation of design changes ay be costly in terms of possible modifications and system support

22

Interactive Workshop

Preliminary Design Review (PDR):

a)Ensures design implementation has met the requirements

b)Ensures that the planned technical approach will meet the requirements

c) Review preparations and readiness for testing, including test procedures

d)Ensures design is ready for formal release to manufacturing

23

System design reviews ensure that:

a) Requirements described in the system specifications are maintained as design evolves

b) Proposed design changes initiated during any phase in the life cycle are documented

c) Proposed design changes initiated during any phase in the life cycle are documented

d) Results constitute basis for preliminary system design and development activity

e) None of the above

Interactive Workshop

24

Configuration Management (CM) is the process that:

a) Identifies the functional and physical characteristics of an item

b) Controls changes to functional and physical design characteristics

c) Records and reports change processing and implementation status

d) All of the above

Interactive Workshop

25

The Critical Design Review, also known as CDR, is generally scheduled:

a) After the completion of detail design, but prior to the release of firm design data for production

b) After the completion of detail design and during the release of firm design data for production

c) During the detail design and development phase of the life cycle

d) During the requirements definition phase of the life cycle

Interactive Workshop

26

The purpose of conceptual design review is to:

a) Experiment with different packaging during formal design

b) Convey final design approach during design review

c) Review and evaluate the reliability baseline of the system

d) Review and evaluate the functional baseline of the system

Interactive Workshop

27

Homework Assignment

Chapter 5 – Textbook page 246 • Answer questions 1, 4, 7, 11 and 13

Read Chapter 6 - Engineering Program Planning

• Pages 247-333

28

Questions? Comments?