Chapter 5: Product Specifications

1. Chapter 5: Product Specifications Product Design and Development Fourth Edition by Karl T. Ulrich and Steven D. Eppinger

2. Product Development Process Concept Development System-Level Design Detail Design Testing and Refinement Production Ramp-Up Planning Remember that we are looking at an overall Product Development Process. We are going into more detail on Concept Development. We did a lecture, quiz and homework assignment on customer needs. Now we are ready to go to the next step in Concept Development.

3. Concept Development Process Development Plan Identify Customer Needs Establish Target Specifications Generate Product Concepts Select Product Concept(s) Test Product Concept(s) Set Final Specifications Plan Downstream Development Perform Economic Analysis Benchmark Competitive Products Build and Test Models and Prototypes Target Specs Based on customer needs and benchmarking Final Specs Based on selected concept, feasibility, models, testing, and trade-offs

4. Product Design Specifications • Basic control and reference document for the design and manufacture • Specific, measurable, testable criteria • “Unambiguous, Understandable, Correct, Concise, Traceable, Traced, Design Independent, Verifiable, Unique, Complete, Consistent, Comparable, Modifiable, Attainable” • Functional decomposition • Performance targets • Constraints (Demands, Musts) • Goals (Wishes, Wants) • Features

5. The Blind Men and the Elephant A Hindu fable by John Godfrey Saxe from Elephants Ancient and Modern by FC Sillar and RM Meyler. The Fourth reached out his eager hand,And felt about the knee.`What most this wondrous beast is likeIs mighty plain,' quoth he;`'Tis clear enough the ElephantIs very like a tree!' It was six men of IndostanTo learning much inclined,Who went to see the Elephant(Though all of them were blind),That each by observationMight satisfy his mind. The First approached the Elephant,And happening to fallAgainst his broad and sturdy side,At once began to bawl:`God bless me! but the ElephantIs very like a wall!' The Second, feeling of the tusk,Cried, `Ho! what have we hereSo very round and smooth and sharp?To me 'tis mighty clearThis wonder of an ElephantIs very like a spear!' The Third approached the animal,And happening to takeThe squirming trunk within his hands,Thus boldly up and spake:`I see,' quoth he, `the ElephantIs very like a snake.' The Fifth who chanced to touch the ear,Said: `E'en the blindest manCan tell what this resembles most:Deny the fact who can,This marvel of an ElephantIs very like a fan!' The Sixth no sooner had begunAbout the beast to grope,Than, seizing on the swinging tailThat fell within his scope,`I see,' quoth he, `the ElephantIs very like a rope!' And so these men of IndostanDisputed loud and long,Each in his own opinionExceeding stiff and strong,Though each was partly in the right,And all were in the wrong! So, oft in theologic wars,The disputants, I ween,Rail on in utter ignoranceOf what each other mean,And prate about an ElephantNot one of them has seen!

6. Writing a good PDS is very difficult • Customer • Regulatory Bodies • Laws of Physics • Functional Analysis • Company Constraints • Social, Political, and Legal Requirements

7. The Product Specs Process • Set Target Specifications • Based on customer needs and benchmarks • Develop metrics for each need • Set ideal and acceptable values • Refine Specifications • Based on selected concept and feasibility testing • Technical modeling • Trade-offs are critical • Reflect on the Results and the Process • Critical for ongoing improvement

8. Product Specifications Example:Mountain Bike Suspension Fork

9. Start with the Customer Needs

10. Establish Metrics and Units

11. Additional Areas to Consider • Physical requirements • Functional requirements • Service environment (comprehensive: insect and bird damage) • Kinematics – type of motion, direction, velocity, acceleration • Forces - direction, magnitude, frequency, resonance, stiffness • Materials – properties of final product, flow of materials, design for manufacturing

12. Design Specification Checklist • Performance At what speed must it operate? How often will it be used (continuous or discontinuous use)? How long must it last? • Environment (during manufacture, storage and use) All aspects of the product’s likely environment should be considered: for example temperature, humidity, risk of corrosion, vibration. • Target product cost This is strongly affected by the intended market. • Competition What is the nature and extent of existing or likely competition? Does our specification differ from the competition? If so, why? • Quantity and manufacture Should it be made in bulk, in batches, or as individual items made to order? Does it have to be a particular shape? Can we make all the parts or must we buy some in? • Materials Are special materials needed? Do we have experience of working with the likely candidate materials? • Quality and consistency What levels of quality and consistency does the market expect for this product? Does every product have to be tested? • Standards Does the product need to conform to any local, international or customer standards? Is the product safe? • Patents Are there any patents we may either infringe or register? • Packaging and shipping How will the product be packaged? How will the product be distributed? • Aesthetics and ergonomics Is the product easy and fun to use? Is it attractive to the right customer? • Market constraints Does a market already exist or must it be created? What is the likely product lifetime? How long do we have to get the product to market? What are the customers’ likes and dislikes? • Company constraints Does the product fit in with company image? Are we constrained in material or process choice? Are there any political considerations? http://labspace.open.ac.uk/mod/resource/view.php?id=194654

13. More Things to Think About • Production – Factory limitations, outsourcing, tolerancing (You may wait on actual tolerances until later – just think about the big picture.) • Assembly • Transport • Costs • Schedule • Life-cycle issues • Human factors

14. Social, Political, Legal • Safety and environmental regulations • STANDARDS • www.ul.com • www.outdoorindustry.com • www.cpsc.gov • www.astm.org • www.nfpa.org • http://www.nssn.org/ • Safety and product liability • Patents and intellectual property

15. Metrics Exercise: Ball Point Pen Customer Need:The pen writes smoothly.

16. Link Metrics to Needs

17. Benchmark on Customer Needs

18. Benchmark on Metrics

19. Assign Marginal and Ideal Values

20. KitKat Crunch Peanut M&Ms Almond Joy Plain M&Ms Chocolate Perceptual Mapping Exercise Opportunity?

21. Now What? Can you get there from here? • Make a functional model of the product • Make a technical model of the product • Make a cost model of the product • Refine the specifications, making trade-offs where necessary. • Flow down the specifications as appropriate • Reflect on the results and the process.

25. Trade-off Curvesfor Three Concepts Specification Trade-offs Estimated Manufacturing Cost ($) Score on Monster (Gs)

26. Set Final Specifications

27. Quality Function Deployment(House of Quality) technical correlations relative importance engineering metrics benchmarking on needs customer needs relationships between customer needs and engineering metrics target and final specs

28. Perceptual Mapping Quiz Crunch Chocolate Name:______________________ CM:______ Name:______________________