ISAT 211 Mod 4-1 1997 M. Zarrugh

Product Development Process Types Market Pull

Process begins with recognition of a market opportunity Technology-Push

New technology pushes new product development Technology Platform

Extension of existing expensive technology to new products Process-Intensive

Strong process requirements severely constrain the product and its development

CustomizedGeneric product and processes are customized to meet specific requirements

ISAT 211 Mod 4-2 1997 M. Zarrugh

ISAT 211 Module 4: Design/Manufacturing InterfaceThe learning objectives of Module 4 are to

– Explain key processes linking product design (engineering) and manufacturing (production)

– Itemize and explain the contents of the product definition file

– Analyze manufacturing costs into its component parts

– Recognize and illustrate design for manufacturing (DFM/DFA) and assembly methodology

– Discuss computer-based technology in manufacturing industry

Engineering Manufacturing

?

ISAT 211 Mod 4-3 1997 M. Zarrugh

Engineering/Manufacturing Interface:DFM/DFA and CAD/CAM

Engineering(Design)

Manufacturing(production)

ENG/MFG Interface

Product definition/ change control

DFM/DFA (cost)CAD/CAM (time)Group Technology

(GT)Computer-Aided

Process Planning (CAPP)

ISAT 211 Mod 4-4 1997 M. Zarrugh

Some Terminology:Alphabet Soup CAD/CAM (more on this in the lab):

– Computer Aided Design (CAD) is a computer-assisted process for the electronic capture of geometry (form and fit) of parts and their arrangements into complete products.

– Computer Aided Manufacturing (CAM) refers to all automated processes in manufacturing, such as computer control of machine tools and materials handling equipment.

Group Technology (GT) is the grouping of parts by similarity in geometry or manufacturing processes (ISAT 331)

Computer Aided Process Planning (CAPP) is the use of computers to generate process plans (detailed instructions for making a part) from CAD data. (ISAT 331)

ISAT 211 Mod 4-5 1997 M. Zarrugh

Design For Manufacturing (DFM) andDesign For Assembly (DFA) or DFM/DFAThe object of DFM/DFA process is to generate a

product definition (form, fit and structure) consistent with minimum cost.

DFM/DFA is iterative and requires cross-functional teams (concurrent engineering) so that form, function, cost and process are considered and optimized simultaneously.

Reduced manufacturing cost is the primary consideration in DFM/DFA.

Many rules have evolved to guide DFM/DFA.

ISAT 211 Mod 4-6 1997 M. Zarrugh

DFM/DFA: Product Definition File A modified product definition file is the main output of the

DFM/DFA process. The file specifies:– Form/Fit: detail and assembly drawings– Structure: how parts fit together (Bill of Material, BOM)– Materials: raw materials properties and heat treatment– Process: how parts are to be made: welded, machined, cast– Specifications: governing standards and critical items– Test procedures: instructions for testing components,

subassemblies and full products– User manual: instructions on how the product will be used– Disassembly/Repair manual: instructions for disassembly, repair

and maintenance

ISAT 211 Mod 4-7 1997 M. Zarrugh

DFM/DFA: Methodology

Initial product definition file

Release modified file

EstimateMFG Costs

Modify file to:

Reduce Components

Costs

Reduce Assembly

Costs

Reduce Overhead

Costs

ConsiderImpact on

Other Factors

ComputeMFG Costs

OK?Y

N

Modify File

ISAT 211 Mod 4-8 1997 M. Zarrugh

DFM/DFA:Manufacturing Cost Analysis

ManufacturingCost

ComponentCost

AssemblyCost

OverheadCost

StandardParts

CustomParts

LaborCost

Equipment/Tooling

Support/Engineering

G & A

ProcessingToolingRaw

Material

ISAT 211 Mod 4-9 1997 M. Zarrugh

Manufacturing Cost:Fixed vs. Variable CostsFixed Costs: independent of how many units produced

– Tooling and other nonrecurring expenses (NRE)

– Investment expenses

– Overhead costs (burden)

– Selling expenses (G & A)

Variable Costs:– Material

– Direct labor (including benefits)

– Machine time

ISAT 211 Mod 4-10 1997 M. Zarrugh

DFM/DFA: Guidelines for DFM Use modular design

Use commercial and standard components

Reduce the number of processing steps

Eliminate unnecessary tight tolerances

Avoid smooth finish if not needed

Consider processing alternatives to machining such as casting and welding

Simplify and optimize process plans

ISAT 211 Mod 4-11 1997 M. Zarrugh

DFM/DFA: Guidelines for DFA Reduce part count

Simplify parts handling

Assemble in the open from the top

Work with gravity

Make parts easy to identify and orient

Use parts that are self aligning and do not tangle up

Eliminate fasteners

Assembly requires only one hand

ISAT 211 Mod 4-12 1997 M. Zarrugh

DFM/DFA:Typical Reported Improvements*

0 10 20 30 40 50 60 70

Increased Reliabilityand Quality

Reduced AssemblyTime

Reduced ProcessingTime

Reduced Part Count

ReducedDevelopment Time

Reduced Part Cost

Users Reporting Improvements (%)

*Based on survey results by Boothroyd and Dewhurst

Reported Improvement

ISAT 211 Mod 4-13 1997 M. Zarrugh

DFM/DFA: A Case Study (Adapted from D. L. Shunk,” Integrated Process Design and Development”, 1992, pp. 33-37.)

Because of significant backlog of microwave components, ma DFM project was initiated to speed up production. Preliminary analysis of the current process “As Is” identified a

component, the waveguide, as the bottleneck. The “As Is” process for the waveguide consisted of

– 23 steps– 10 stations– 17 weeks to complete

Step 1 is sawing which could not be controlled to produce desired tolerance. By standardizing lengths, holding fixtures were introduced to provide the desired accuracy.

ISAT 211 Mod 4-14 1997 M. Zarrugh

DFM/DFA: Waveguide Case Study “As Is” Process

nStep #

1

nStation #

2

3

4

5

6 7

8

9

10

ISAT 211 Mod 4-15 1997 M. Zarrugh

DFM/DFA: Waveguide Case Study Continued A reliable supply of raw stock is critical for on-time production. A

strategic alliance was formed with a vendor who became the primary source of the stock.

Through process simplification, the processes were consolidated into one dedicated cell (area).

Certain part routings were changed to improve flow. The new “To Be” process flow consists of:

– 12 steps (vs. 23 before)

– 2 stations + 1 cell (vs. 10)

– 2 weeks completion (vs. 17 weeks) The positioning strategy of “make-to-stock” was replaced with “make-

to-order” because of increased responsiveness Cost was reduced by 28%

ISAT 211 Mod 4-16 1997 M. Zarrugh

DFM/DFA: Waveguide Case Study “To Be” Process (Wave Guide Cell)

9+3 steps2 stations + 1 cell Cell

ISAT 211 Mod 4-17 1997 M. Zarrugh

Why Do Companies AcquireNew Technologies? To accomplish the following strategic goals:

Reduced cost of product, service or process

Faster product development or shorter time-to-market

Improved quality of product or service

Increased flexibility and improved responsiveness to changing customer needs or market climates

ISAT 211 Mod 4-18 1997 M. Zarrugh

Computer-Based Technology In Manufacturing Industry: Recent TrendsAutomation of manufacturing processes using

computer control technology (CAM: NC/CNC) Integration of automation islands via information

technology (CIM, MRP, DBMS, PIM)Industrial roboticsFlexible (cellular) Manufacturing Systems (FMS)

CAM

MRP

DBMSPIM

FMS

CAD

ISAT 211 Mod 4-19 1997 M. Zarrugh

Benefits of Implementing Computer-based Technology in MFG Industry

Reduction in engineering design cost

Reduction in overall lead time

Increased product quality (yield)

Increased engineering effectiveness

Increased production productivity

Increased equipment utilization

Reduction in work-in-process

Reduced labor cost

Benefit Extent15-30%

30-60%

2-5 times

3-35 times

40-70%

2-3 times

30-60%

5-20%

ISAT 211 Mod 4-20 1997 M. Zarrugh

Recent Computer-Based Technology Innovations In Production ManagenetOffice automation: word processing, spreadsheets,

E-mail, voice mail and faxProduct data management systems: electronic

capture and distribution of documentsElectronic data interchange (EDI): electronic

exchange of data between systems and firmsDecision support and expert systems: analysis of

decision alternatives and selecting the “best”Communication: networked computer systems

linking all units within an enterprise

ISAT 211 Mod 4-21 1997 M. Zarrugh

Operational Benefits of New Technologies in Manufacturing

Benefits are strategic and difficult to quantify: Increased labor productivity: leveragingDecreased material cost: fiber optics vs. copperReduced inventory cost: better scheduling and JITImproved process quality: consistency from

automationImproved product quality and reliabilityReduced cycle times and shorter delivery times

ISAT 211 Mod 4-22 1997 M. Zarrugh

Technology Adoption Risks

Untested technology may disrupt operations

Rapid obsolescence of technology

Delays, retraining and errors caused by the introduction of new technology are disruptive

Management may abandon the technology too quickly due to early problems

Uncertainties of overall economic impact

Questions?