Presentation on theme: "Chapter 6: Product Specifications"— Presentation transcript:
1 Chapter 6: Product Specifications Product Design and DevelopmentFifth Editionby Karl T. Ulrich and Steven D. Eppinger
2 Reflection on Customer Need Statements Access objects in the bag quickly and easily.The person must be able to retrieve items of interest in an unawkward fashion.A user should be able to access common items while standing up with minimal effort.Be able to locate items easily in the bag.Customer needs an easier way to pay for purchases.More storage options for better organization.New location for checkbook.Person needs a way to see into the backpack easily so that they can find checkbook easier.Customer needs bag with compartments they can reach while wearing the bag.A wallet with a debit card and built in ID.Hands free way of holding bag so both hands can be used in looking for stuff.Velcro pockets on the outside to hold wallet, checkbook and such.Thumbs up thumbs downAccess objects in the bag quickly and easily – this is good for a customer need; however, it is recommended to only include one item in a need statement. Access objects in the bag quickly. Access objects in the bag easily.“Unawkward” is actually awkward.Why common? Why only standing up?I like be able to locate items easily. I would probably omit in the bag.Customer needs an easier way to pay for purchases – oops this isn’t about the bag.More storage – this is how.New location for checkbook – this is howSeeing is also how,The rest are all hows…
3 Suggested SolutionsSee how the leather on the bottom of the bag is all scratched; it’s ugly.When I’m standing in line at the cashier trying to find my checkbook while balancing my bag on my knee, I feel like a stork.This bag is my life; if I lose it I’m in big trouble.There’s nothing worse than a banana that’s been squished by the edge of a textbook.I never use both straps on my knapsack; I just sling it over one shoulder.The bag maintains its original appearance with use.Bag allows easy access to itemsBag is easy to find.The bag protects fragile items from damage.The bag can rest securely in multiple modes (either or both shoulders.)The bag can be carried comfortably in multiple modes (one shoulder strap, two shoulder straps, or hand hold.)
4 Product Development Process PlanningConceptDevelopmentSystem-LevelDesignDetailDesignTesting andRefinementProductionRamp-UpRemember 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.
5 Concept Development Process PlanIdentifyCustomerNeedsEstablishTargetSpecificationsGenerateProductConceptsSelectProductConcept(s)TestProductConcept(s)Set FinalSpecificationsPlanDownstreamDevelopmentPerform Economic AnalysisBenchmark Competitive ProductsBuild and Test Models and PrototypesFor Senior Design, you may only get to the point of identifying target specs.Target SpecsBased on customer needs and benchmarkingFinal SpecsBased on selected concept, feasibility, models, testing, and trade-offs
6 Product Design Specifications Basic control and reference document for the design and manufactureSpecific, measurable, testable criteria“Unambiguous, Understandable, Correct, Concise, Traceable, Traced, Design Independent, Verifiable, Unique, Complete, Consistent, Comparable, Modifiable, Attainable”Functional decompositionPerformance targetsConstraints (Demands, Musts)Goals (Wishes, Wants)Features
7 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 like Is mighty plain,' quoth he; `'Tis clear enough the Elephant Is very like a tree!'It was six men of Indostan To learning much inclined, Who went to see the Elephant (Though all of them were blind), That each by observation Might satisfy his mind.The First approached the Elephant, And happening to fall Against his broad and sturdy side, At once began to bawl: `God bless me! but the Elephant Is very like a wall!'The Second, feeling of the tusk, Cried, `Ho! what have we here So very round and smooth and sharp? To me 'tis mighty clear This wonder of an Elephant Is very like a spear!'The Third approached the animal, And happening to take The squirming trunk within his hands, Thus boldly up and spake: `I see,' quoth he, `the Elephant Is very like a snake.'The Fifth who chanced to touch the ear, Said: `E'en the blindest man Can tell what this resembles most: Deny the fact who can, This marvel of an Elephant Is very like a fan!'The Sixth no sooner had begun About the beast to grope, Than, seizing on the swinging tail That fell within his scope, `I see,' quoth he, `the Elephant Is very like a rope!'And so these men of Indostan Disputed loud and long, Each in his own opinion Exceeding 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 ignorance Of what each other mean, And prate about an Elephant Not one of them has seen!As a Design Engineer, you will be taking different views of the product. Every view has a slightly different perspective. What the customer wants is the elephant, and you have to figure out how to do that.
8 Writing a good PDS is very difficult CustomerRegulatory BodiesLaws of PhysicsFunctional AnalysisCompany ConstraintsSocial, Political, and Legal RequirementsGive example from Clinch River Liquid Metal Fast Breeder Reactor Closure Head Data Acquisition System – case about differentiating position to get velocityHeat treat vs hardness
9 The Product Specs Process Set Target SpecificationsBased on customer needs and benchmarksDevelop metrics for each needSet ideal and acceptable valuesRefine SpecificationsBased on selected concept and feasibility testingTechnical modelingTrade-offs are criticalReflect on the Results and the ProcessCritical for ongoing improvement
10 Product Specifications Example: Mountain Bike Suspension Fork
11 Start with the Customer Needs Which of these are “not so good” customer needs statements?“instills pride”?“is not contaminated”?
12 What are some customer needs for the catapult-like device? Size matters not.Cool,size constraints – not too big and not too small, just rightWeight constraints – not to heavy and not too lightTime to change from one set up to the nextAbility to determine output of device
13 Establish Metrics and Units Establishing Metrics requires experience and knowledge in the area. If you are unfamiliar, look at competitors products and see what they report. For example, most cars report their engine size – so this is probably important. There will be other things that are important that you may not discover until you are into the design process.
14 Metrics Exercise: Ball Point Pen Customer Need: The pen writes smoothly.They have a good discussion of this.
15 Additional Areas to Consider Physical requirementsFunctional requirementsService environment (comprehensive: insect and bird damage)Kinematics – type of motion, direction, velocity, accelerationForces - direction, magnitude, frequency, resonance, stiffnessMaterials – properties of final product, flow of materials, design for manufacturingThese additional areas can have a significant effect on your product. For the first round of selecting metrics, they are definitely worth spending time on. If you miss something crucial, you are in BIG trouble.
16 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?
17 More Things to Think About Production – Factory limitations, outsourcing, tolerancing (You may wait on actual tolerances until later – just think about the big picture.)AssemblyTransportCostsScheduleLife-cycle issuesHuman factors
18 Social, Political, Legal Safety and environmental regulationsSTANDARDSSafety and product liabilityPatents and intellectual property
19 Link Metrics to NeedsAn empty row means there is something the customer wants that he isn’t getting. An empty column could mean two different things: There is something that you’re giving the customer that they don’t want, OR, there is a regulatory mandate, OR, there is something that the customer doesn’t talk about because they assume they will always have it. BE CAREFUL here
20 Benchmark on Customer Needs This should be customer perceptions. Customer perceptions may be different from the facts, but they are still customer perceptions. Old example of Ford vs. Toyota truck.
21 Benchmarking Product Design by Otto and Wood, 2001 Look at your customer needs and your metricsForm a List of Related or Competitive ProductsConduct an Information SearchEstablish Best-in -Class CompetitorsDevelop SpecificationsLess thanGreater thanRangeDiscrete valuesExactly X
22 Sources of Product Information LibraryThomas RegisterMarket Share ReporterNational Bureau of StandardsCensus of ManufacturesMoody’s Industry ReviewConsumer Reports MagazineTrade MagazinesPatentsMarket Research DatabasesDIALOG, Predicasts, American DemigraphicsWebVendorsTechnical SpecialistsExperts/Friends in IndustryNAICS (North American Industry Classification System) Codes
23 Here are some ideas that you might like Here are some ideas that you might like. Please feel free to generate your own!
25 DOE 1 DOE 1 CUT CUT CUT CUT Design for Design for FOLD DOWN FOLD UP FIRSTCUTDOE 1BODY 2WIDTHBODY 1WIDTHFOLD UP ENDFOLD UPWING 1LENGTHWING 2LENGTHFOLD UPCUTBODY 2LENGTHBODY 1LENGTHCUTHELICOPTER 1CUTHELICOPTER 2Design forDOE 1Design for
30 Now What? Can you get there from here? Make a functional model of the productMake a technical model of the productMake a cost model of the productRefine the specifications, making trade-offs where necessary.Flow down the specifications as appropriateReflect on the results and the process.I’m adding a step here. Let’s insist that they do some functional modeling.
36 relationships between Quality Function Deployment (House of Quality)technicalcorrelationsrelativeimportanceengineeringmetricscustomerneedsbenchmarking on needsrelationships betweencustomer needs andengineering metricstarget and final specs