560 likes | 709 Views
Engineering 11. Formulate Design Prob. Bruce Mayer, PE Licensed Electrical & Mechanical Engineer BMayer@ChabotCollege.edu. Example Improve MotorCycle. Other Useful Information What is the target cost-to-manufacture? Which is more preferred: low-end torque or high-end speed?
E N D
Engineering 11 FormulateDesign Prob Bruce Mayer, PE Licensed Electrical & Mechanical EngineerBMayer@ChabotCollege.edu
Example Improve MotorCycle • Other Useful Information • What is the target cost-to-manufacture? • Which is more preferred: low-end torque or high-end speed? • What is the anticipated production run quantity? • What types of instruments are preferred, digital and or analog? • What are the desired service intervals?
Formulating Design Problems • Designing a high-performance motorcycle • What is a “design problem?” • What is the “solution” to a design problem? • How do we solve a design problem? • Steps in formulating the Design Problem • Customer & Company requirements • Engineering Design Specifications • Gaining Consensus • Quality Products • QFD/House of Quality
What is a design problem? • An opportunity to make and sell a new product • Need to fix an existing product • Make and sell a variant of an older design [Customer or Company Requirements]↓define↓[”Function”]
Example Improve MotorCycle • What info would help us understand this design problem? • How quickly should the MotorCycle accelerate to 60 mph? • What should the top speed be? • Is fuel consumption less important than acceleration? • What riding comforts are expected? • Is an electric starter desired? • Will the customer tolerate a liquid cooling system? • Will customer care about aesthetics?
“Solution” to a Design Prob • Set of Drawings & Bills of Materials • Predicted performance calculations • Test reports on prototypes • Manufacturing specifications • Estimates of sales-revenue, costs, profit • [“design” ready for manufacture] →defines→ [“Form”]
How to Solve a Design Problem? Design problem (function, customer need) “Formulate” first!i.e., Decide on needed Decisions... ? Decision making processes and activities Solution (form, manufacturable product design)
Decisions & Info Flow Formulating process Literature, Surveys Market Studies Focus Groups Observation Studies Benchmark Studies Customer needs? Competition? Seek info Functional requirements? Targets? Constraints? Evaluation criteria? probe Interpret Summarize revise Gain consensus Preliminary design specifications Review discontinue Obtain management approval continue Engineering Design Specification
Steps In Formulating Design Prob • obtain a detailed understanding of the design problem; i.e., the application • document our understanding in an Engineering Design Spec (EDS) • choose a solution strategy • develop a project plan (scope of work, budget and schedule) • establish a consensus among team members & management
1. Obtain a Detailed Understanding • Need ACCURATE Information on • Company Requirements (easy) • CUSTOMER Requirements (hard) • The “Requirements” for a Design typically divide into two categories • PERFORMANCE Requirements • Constraint Requirements • e.g., Meet N.E.C. Electrical Code • Business Impact Revenue, Profit, RoI
Market Requirements StateMent • The “MRS” is Also often called the Market Requirements Document (MRD) • MRS Most Often Prepared by the Technical Marketing Team With Extensive Consultation with • Upper Management • Senior Design Engineers
MRS/MRD Purpose • Provide an outline of the prospective product for all interested parties • Investors, Sales Engineers, Finance, Upper Management, Engineering, others • Provide enough information for engineering to write a functional design specification for the product • The Design Spec if Often Called the Engineering Design Specification (EDS)
MRS ↔ Design Engineering • Once the New Product Has been Approved (i.e., Meets the Company RoI Requirement) The Design Engineering Focuses on These Portions of the MRS • Product Performance • Becomes the Heart of the Engineering Design Spec (EDS) • Code-Compliance Constraints • Product Cost Targets
Customer Req’s for MotorCycle • Function/Performance: • start engine quickly • support rider(s) comfortably • Operating • Tolerated road shock: PotHoles, Bumps • Run in wet, cold, high altitude Environs • Other • Long maintenance intervals • Good fuel economy
MRS/MRD Information Sources • Customer Surveys • Market Studies • Technical & Trade Literature • Focus Groups • Observation Studies • Benchmark Studies • Trade/Industry Groups • SIA, SEMI, SemaTech, etc.
Company Req’s for MotorCycle • Sales & Marketing: • need product in 24 months, • sale price competitive • Manufacturing • Produce 5,000 units per year • Use existing manufacturing plant • Financial • $300,000 R&D budget • minimum 20% RoI, 3 Year PayBack
Function & Performance Functions and their Priority Engineering characteristics With units & limits Performance Targets Satisfaction Goals Size & Weight Power Use Operating Environment Air temp. Humidity, Elevation Corrosion (e.g. SeaWater) Shock & Vibration Cleanliness (e.g. Operating Room) Radiation, Other Generic Customer Requirements
Other Issues Economic (Affordability) Geometry Maintenance Repair Retirement Reliability Other Issues Robustness Safety Pollution Ease of use Human Factors Appearance Generic Customer Requirements • Notice Focus on Function, NOT Form
Marketing Total Available Market (TAM) Competition Sales Strategy Time to market Pricing Advertising Market Share Manufacturing & Operations Production quantity Processes, Materials New factory equip. Warehousing & dist. After Sales Support Warranty Support Returns & Repairs Generic Company Requirements
Financial Product Development Investment Cash Flow Return on investment (RoI) Return on Controllable Assets (RoCA) Other Regulations, Standards, Codes Patents / intellectual property Company Image e.g., a Pharmaceutical Co. would not develop a Cigarette Product Liability Generic Company Requirements
Must all requirements be satisfied? • Requirements can be separated into: • NEED-to-Have items • Product WILL FAIL in MarketPlace w/o these • These “Must-Have” items Become “Constraints” on the Design • Nice-to-Have items • Produce will be MORE COMPETITIVE w/ these • These “Desirable” Features should be Weighted by “Importance-to-the-Market” • Weighting is Typically a Marketing Engineering Fcn
MotorCycle Importance Wts • Example of Customer importance weights by sub-function Sub-function Weight start engine quickly 15 % support rider(s) comfortably 10 % transport rider(s) fast 50 % steer bike easily 20 % absorb road shocks 5 % TOTAL 100 %
Translate MRS/MRD to EDS • A CRITICAL Step Done by Senior Marketing & Design/System Engineers • How will we know when we have designed a product that satisfies the customer? e.g. • Customer says, “I want a fast motorcycle.” • What does “fast” mean? Could it be: • 120 mph top speed? • 32 ft/sec2 (1 G) acceleration? • 150 Hz (9 kRPM) engine frequency?
Sub-function Engineering Characteristic Units Limits start engine quickly cranking time seconds ≤ 6 secs support rider(s) comfortably cushion compression inches transport rider(s) fast acceleration top speed 0-60 mph feet/ sec2 mph/kph seconds ≥ 32 ft/s2 ≥ 90 mph ≤ 6 secs steer bike easily steering torque turning radius pound-ft feet Absorb road shocks suspension travel inches > 5 in. MotorCycle: Translation to EDS • Engineering Specs are Objective & Quantitative
Engineering Characteristics • Engineering Design Spec Elements are: quantities that measure the “performance” of a candidate design with respect to specificcustomer required functions
MRS→EDS War-Story • Customer Needs for BPSG & USG Films for IC production • Then What it the Bubbler TEMPERATURE CONTROL Spec • This QuestionLead to the a22 Pg Paper:
Usually Prepared by MARKETING Engineers, NOT by Design Engineers Large Amount of JUDGMENT in Fcn Construction The Design Engineers may USE them to Guide Design Decisions Tabular Function Amount of satisfaction Value Most satisfied 1.0 Very satisfied 0.9 Moderately satisfied 0.8 Somewhat satisfied 0.6 Hardly satisfied 0.3 Not satisfied 0.0 Customer Satisfaction Function(s)
Graphical Function for MotorCycle TopSpeed Customer Satisfaction Function(s) Shape of the Curve Depends on JUDGMENT Satisfaction 1.0 TopSpeed(mph) 0.0 90 150
2. Document UnderStanding in EDS • The Engineering Design Specification is a Quantitative listing of the critical parameters, specifications, targets and requirements for the product you are designing. • It is a statement of what the product should BE and should DO. • Detail is added as the design grows. • The EDS is driven by customer needs. It is intended to show WHAT you are trying to ACHIEVE, NOT what you will end up with.
3. Choose a Solution Strategy • list possible alternative solution strategies, • for example: discontinue product, variant design, original design, etc • estimate the expected benefits and the costs of each alternative • assess the risk of each alternative strategy • establish criteria to evaluate alternatives • (e.g. benefits/costs, risk, Return on investment) • evaluate the alternatives • select the best alternative
Formulation original design selection design part design Concept Design variant design Configuration Design Configuration Design Parametric Design Parametric Design Parametric Design Detail Design Detail Design Detail Design Detail Design Formulation Produces Strategy
4. Develop a Project Plan • Will be Covered in Detail in Chp 14 Concept Definition & Planning Development Pre-Production Production Go/ No Go Go/ No Go Go/ No Go Go/ No Go • Evaluate the market opportunity • Clarify the product concept • Assessstrategic fit • Validate the opportunity • Clearly define the product • Fully plan the project • Develop the product • Develop production and support processes • Plan the market introduction • Transition the product to volume production • Begin market introduction • Ramp-up production • Verify distribution and support processes • Achieve stable operations Stage Objectives Does the productwarrant further definition? Does the productmeet customerneeds, and does itwarrant investmentin full development? Does the productmeet expectationsand remain viablewithin the requiredtime frame? Do test results andmarket introductionpreparationsdemonstrate launchreadiness? Have projectobjectives beenachieved, and canthe Core Team bedisbanded? Key Questions
5. Establish a Consensus • “Building In” the Consensus • Consensus is INTEGRAL To the Process • If all team members follow the previous five steps to a sound formulation, they will: • Have a common understanding of the “problem,” • All Understand WHY, • All Know WHAT has to be done and WHEN, and • All Commit to WHO & HOW-MUCH
Quality What is it? • TIME Magazine Survey responses • Works as it should • Lasts a long time • Is easy to maintain • Garvin, Commenting on Eight Dimensions of Quality, Harvard Business Review, Nov/Dec 1987 • Performance • Reliability • Serviceability • Conformance to conventions/standards • Perceived quality reputation of manufacturer • Features • Durability • Aesthetics
All Done for Today MotorCycleEngineBluePrint Assy DWG
Engineering 11 AppendixQFD & HoQ Bruce Mayer, PE Registered Electrical & Mechanical EngineerBMayer@ChabotCollege.edu
Quality Function Deployment, QFD • Quality Function Deployment (QFD) • Team based visual, connective process • Focuses on customer needs throughout entire product development process • QFD is a systematic process • Helps identify customer desires and to “deploy” them through all functions and activities of the organization • House of Quality (HoQ) • Use of large visual displays or diagrams to • Focus decision making interactions of multifunctional teams • Visually display relevant information for ready reference • Document decisions in a graphical Form
Quality Function Deployment, QFD • Team discussions and research results summarized in House of Quality (HoQ) diagrams • Product • Part • Process • Production information • Representatives from all parts of company involved in creating and refining HoQ diagrams • Desire to achieve high level of consensus
HoQ for Product Planning • Systematic, graphic representation of product design information • Organized as matrix of rooms with roof and basement • HoQ diagram is not the real value • Real value is in thediscussion and consensus acquired while constructing the diagram
HoQ for Product Planning • Team gathers information related to product design • Customer requirements • Customer importance weights • Engineering characteristics (technical specifications) • Correlation ratings of requirements & characteristics • Benchmark satisfaction ratings • Coupling between technical specifications • Benchmark performance values • New product design target values
HoQ FloorPlan 8 Coupling • Group method • Encourages discussion • Forces agreement between team members • Structures information 3 Engineering Characteristics 5 Benchmark Satisfaction Ratings 1 Customer Requirements 4 Correlation Ratings 2 Importance Weights 6 Benchmark Performance 7 New Product Performance Targets
HoQ for Product Planning • Room 1 Customer requirements • Summarized in rows of 1st column • Clear list of functions and subfunctions from customer’s view point • Customer wording used to express voice of the customer • Contains only most important requirements (usually less than 25) • Room 2 Customer importance weights • Adjacent to customer requirements column • Use values between 0.0 and 1.0 (0-100%) • Importance weights sum to 1.0 (100%)
HoQ for Product Planning • Room 3 Engineering Characteristics (TS) • Top row underneath roof triangle • List of quantitative performance factors with units • Arranged in a row vector • Quantifies the customer satisfaction for each customer requirement • Room 4 Correlation ratings matrix • Cells at intersections of rows and columns indicate the amount of correlation between the requirements and specifications • Use for positive correlation • 1 ≡ low, 3 ≡ medium, 9 ≡ high • Use for negative correlation • −1 ≡ low, −3 ≡ medium, −9≡high
HoQ for Product Planning • Room 5 Benchmark satisfaction ratings • Right of correlation matrix • Customer ratings for competitive products for satisfaction of each requirement • Include own current products if any • Ratings between 0.0 and 1.0 • Room 6 Benchmark performance • Below of correlation matrix • Rating for each benchmark product with respect to the Technical Specs (TS) in Room 3 • Room 7 New product targets • Below benchmark performance in the basement • List performance targets for new product
HoQ for Product Planning • Room 8 Coupling matrix • Roof triangle • Values to estimate coupling or interaction between technical specifications • For positive correlation: 1 ≡ low, 3 ≡ medium, 9 ≡ high • For negative correlation: −1 ≡ low, −3 ≡ medium, −9≡high • Uncoupled specifications can be optimized one by one • Inversely coupled specifications require compromises (strong but light)
Production Characteristics Process Characteristics Production Planning Part Characteristics Process Planning Engineering Characteristics Part Design Customer Requirements Product Planning QFD method uses cascading Houses of Quality Voice of the customer
EDS Example Elements • These Items Might appear in an EDS • Intended market • Product cost(s) • Operating environment • Engineering performance • Product operators users • Ergonomics • User interface • Dimensions • Weight • Materials • Product life • Service life • Storage shelf life • Reliability • Mean time to failure