Lecture Notes 1 - Design Process, Design to Cost PDF

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lecture notes from 2018, me270, lecture notes 1....

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Function, Quality, and Cost Design Process

Lecture Notes 1: The Design Process; Design-to-Cost

What is a “Product Design Specification” (PDS)? Concurrent Engineering aPriori Cost Analysis Manufacturing Process Selection

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ME 270, Leon Liebenberg

Key steps in Design for Manufacturability

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Manufacturing Principles, Methods, and Equipment

Hierarchy of manufacturing processes: • What is theoretically possible (“in principle”) ? • What is practically possible (“method”)? • What is possible with the equipment used for that method?

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ME 270, Leon Liebenberg

Function, Quality, & Cost • Matching design requirements to suitable manufacturing processes is at the heart of design-for-manufacturability • Trade-off! • In this course, we will usually analyze design requirements and related manufacturing processes i.t.o. function, quality, and cost

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Inputs to the Design Process

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ME 270, Leon Liebenberg

Stages of the Design Process Identify Need

Ideation

Develop Product Design Spec

Generate Design Ideas

Analyze and Select Design

Identify Need Need: driven by marketing or business plan, customer request, cost reduction, or desired design improvement

Detail Design Prototype Development

Iterate any steps, as necessary

Do Background Research

Build Prototype Evaluate

Manufacture

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Stages of the Design Process Identify Need

Ideation

Develop Product Design Spec

Generate Design Ideas

Analyze and Select Design

Detail Design Prototype Development

Iterate any steps, as necessary

Do Background Research

Build Prototype Evaluate

Manufacture

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ME 270, Leon Liebenberg

Do Background Research Background: What is currently available? What is the competition? Perform benchmarking, patent search.

Stages of the Design Process Identify Need

Ideation

Develop Product Design “Spec”

Develop Product Design Spec

Product Design Specification (PDS) • Identify product/design requirements • Review all 28 Primary Elements from performance through cost, to disposal/recycling requirements • Objective/measurable - with units (metrics) For example: • Able to support 500 N of vertical force • Produce flow rate of 200 l/s • Maintain operating temperature of 32ºC • Requires no tools for assembly

Generate Design Ideas

Analyze and Select Design

Detail Design Prototype Development

Iterate any steps, as necessary

Do Background Research

Build Prototype Evaluate

Manufacture

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Primary Elements of PDS

AESTHETICS

INTELLECTUAL PROPERTY

TESTING

COMPANY CONSTRAINTS

PROCESSES QUALITY & RELIABILTY

ERGONOMICS

DISPOSAL MARKET CONSTRAINTS

TIMESCALES

CUSTOMER SAFETY STANDARDS PRODUCT LIFE SPAN

PRODUCT

ENVIRONMENT QUANTITY

TARGET PRODUCT COST

MANUFACTURING FACILITY

ME 270, Leon Liebenberg

LIFE IN SERVICE SHIPPING

COMPETITION

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MAINTENAMCE SHELF LIFE

PERFORMANCE

ETHICS & SOCIETY

MATERIALS

SIZE & WEIGHT

PACKAGING

Primary Elements of PDS – ME 270

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PDS comparison for ME 170, 270, 370, & 470 ME 170

ME 270

ME 370

ME 470

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ME 270, Leon Liebenberg

Stages of the Design Process Identify Need

Ideation

Develop Product Design Spec

Generate Design Ideas

Analyze and Select Design

Detail Design Prototype Development

Iterate any steps, as necessary

Do Background Research

Build Prototype Evaluate

Manufacture

Generate Design Ideas Idea generation: • BRAINSTORMING – use mult. tools • SKETCH IDEAS – initial simple 2D, then Refine to 3D • Rough Prototyping with expendable materials (e.g. paper, cardboard, foam),

Rules of Ideation • • • •

No criticism or ridicule Free flow of ideas Record ALL suggestions Do not prejudge idea

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Stages of the Design Process Identify Need

Ideation

Develop Product Design Spec

Generate Design Ideas

Analyze and Select Design

Detail Design Prototype Development

Iterate any steps, as necessary

Do Background Research

Build Prototype Evaluate

Manufacture

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ME 270, Leon Liebenberg

Analyze and Select Design • Preliminary design evaluation and calculations • Use structured concept selection process (e.g. Pugh chart/matrix) • Present to client and explain/defend decision

Stages of the Design Process Identify Need

Ideation

Develop Product Design Spec

Generate Design Ideas

Detail Design

Analyze and Select Design

Detail Design Prototype Development

Iterate any steps, as necessary

Do Background Research

Build Prototype Evaluate

• CAD (Detailed engineering drawings) • Analysis: Use analytical and computational tools • Bill of Materials

Manufacture

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Stages of the Design Process Identify Need

Ideation

Develop Product Design Spec

Generate Design Ideas

Analyze and Select Design

Detail Design Prototype Development

Iterate any steps, as necessary

Do Background Research

Build Prototype Evaluate

Manufacture

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ME 270, Leon Liebenberg

Build Prototype Evaluate Prototyping and Evaluation: • Measure performance • Does it work as predicted? • Compare against design specs & pre-set metrics • Redesign prototype as necessary • Debug prototype and manufacturing processes. • Determine prototype vs. production cost … is it scalable?

Stages of the Design Process Identify Need

Ideation

Develop Product Design Spec

Generate Design Ideas

Analyze and Select Design

Detail Design Prototype Development

Iterate any steps, as necessary

Do Background Research

Build Prototype Evaluate

Manufacture

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“Design Thinking”

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ME 270, Leon Liebenberg

Manufacture • ME 170/270: Mass Production • ME 470: Production for Client Needs

Knowledge and Learning Marketing Knowledge

Cost of Change

High 0

Percentage

100 90

0 0

Knowledge of Design Behavior

80 70

0 0

60 50

0 Process 0 Capability 0 Knowledge 0

40 30 20 10

Design Freedom to Make Changes

0

Low

Time Into the Design Process

Production

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Why DtC? Prior to the early 90’s Marketing

Design

Manufacturing

Cost Calculation

Cost as a design factor starting to surface Marketing

Conceptual Design

Detailed design

Process Selection

Cost Estimate

70% product cost is committed at early stages of design, only 6% of development cost is spent on design itself… 20

ME 270, Leon Liebenberg

Concurrent Engineering “Concurrent engineering” = Simultaneously doing product design + design of manufacturing system

Marketing Knowledge

Cost Knowledge

Material Choice

Product Idea

Mfg. Process Selection

Detailed Design Dev.

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Design to Cost - Implementation Goals: • Estimating cost directly from a part model’s geometric features • In real-time during CAD modeling with little to no extra time and without expert manufacturing knowledge • In an integrated environment with direct access to enterprise cost data (e.g. updated material cost, machine parameters, labor rates, overhead rates, etc.)

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ME 270, Leon Liebenberg

Cost Analysis • Variable Cost

• Fixed Cost

– Costs that vary with the amount of product output

– Costs that are independent of

• If your company is a bakery, which are fixed costs: flour

light bulbs

cupcake holders

oven energy

capital depreciation

boss’ salary

building rent

• Fully Burdened Cost – Combination of Fixed and Variable costs on a per part basis ME 270,

© 2015 University of Illinois at Urbana-Champaign, All Rights Reserved

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Product Cost Components Cost breakdown of a bicycle

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ME 270, Leon Liebenberg

slide 23

Cost Factors Why is die casting more costly than sand casting?

Tooling is a lot more expensive and labor costs are roughly double 25

Cost Factors When to choose automated machining?

Automated machining moves costs from labor to tooling 26

ME 270, Leon Liebenberg

Manufacturing Process Selection

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Examples of Costs: Sand Casting

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ME 270, Leon Liebenberg

Examples of Costs: Machining

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Examples of Costs: Injection Molding

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ME 270, Leon Liebenberg

Example: A Classification of Manufacturing Processes Familiar groupings of manufacturing processes. Final column = a list of possible attributes for a specific process.

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ME 270, Leon Liebenberg...