4th Edition Chapter 21 Design Step #1: Defining the Problem

Welcome to the Design Studio What You Will Learn Design in not a closed or open one-dimensional exercise – need teams to interact in design Conflicting requirements mean you have to assess what is needed Once you have a problem understood, you need a List of Specifications Demanded and Wished for constraints Milestone # 1: Clarification of the Task

Problem Definition Read the specifications fully to determine if the correct problem is being posed. E.g., Complaints that a tall building's elevator is slow may mean you have to install another elevator at great expense or it might mean put soothing music on the main floors and provide clientele with morning coffee Exploring Engineering

Blimp Problem Competition required that Nerf® balls be retrieved and returned to a blimp base. But who said you needed to build a blimp to perform retrieval? But, if this were a commercial contract, you would have to check first with your customer if you deviate from a blimp design Exploring Engineering 4

List of Specifications Specifications may be of 2 kinds: 1) Demanded design elements and 2) Wished for design elements Don’t confuse the two! Be specific as possible and use numbers where possible e.g., not “heavy” but “2.5 kg” etc. Exploring Engineering 5

Table of Common Categories for Specifications Performance Manufacture Geometry Standards Materials Safety Energy Transport Time Ergonomics Cost Weight Exploring Engineering 6

Example: Design and Build an "Autogolfer" Separate out Demand (D) from Wish (W) Specs D Cost < $600 Single unit for drive and putt Remote Control Portable Max # of RC servers = 8 Passes safety inspection Can’t touch ball until shot Supports fit within 3 ft circle Exploring Engineering 7

Example Continued Performance specifications D Remote triggering Can’t touch ball until stroke Adjustable drive 15 to 250 yards Adjustable putting 0 to 15 yards Operate on 45º slope W Sink 95% of putts  3 ft Driving 5 yards Exploring Engineering 8

Example Continued Geometry D 8 RC servos Single unit 3 foot circle Materials W Not degrade in rain snow, 30ºF Time Ready to go < 14 weeks Cost  $600 (exclusive of radios) Manufacture Can use available tools Necessary skills in team Off-the-shelf parts as possible Exploring Engineering 9

Example Concluded Standards D Radios OK for FAA regs Safety Must pass safety review Transport Must be portable W Should fit in a car or small truck Exploring Engineering 10

Assignment: Design Milestones and Clarification of the Task If general design project 1) Interview customer or 2) Take product survey Typed list of specs If design competition 1) Review rules Ask to clarify Typed list requirements Exploring Engineering 11

Design Workshop Design is inherently multidimensional Accordingly we need a method that will allow for the competing functionalities Start by envisaging the specifications on the item to be designed Form teams to share and stimulate ideas 1st cut: separate into what is necessary and what might help Design milestone: Clarification of the Task Exploring Engineering 12