1 SPIRIT Silicon Prairie Initiative on Robotics in Information Technology Engineering Design Tools

2 SPIRIT Conceptual Design 5. Establish design specifications 6. Generate alternatives Client Statement (Need) Preliminary Design 7. Model or analyze design 8. Test and evaluate design Detailed Design 9. Refine and optimize design Final Design (Fabrication Specs & Documentation) Problem Definition 1. Clarify objectives 2. Establish user requirements 3. Identify constraints 4. Establish functions Design Communication 10. Document design Design Process

3 SPIRIT Convergent (left brain) and Divergent (right brain) Thinking

4 SPIRIT Heuristics  A heuristic is anything that provides a plausible aid or direction in the solution of a problem.  Heuristics are usually unjustified and potentially fallible. is  Engineering design is the use of heuristics.  Heuristics are used to cause the best change in a poorly understood situation within the available resources.

5 SPIRIT Sample Engineering Heuristics  Rules of Thumb and Orders of Magnitude  Attitude-Determining Heuristics  Risk-Controlling Heuristics  Resource Allocation Heuristics  Miscellaneous Heuristics

6 SPIRIT Rules of Thumb  Ambient temperature 20  C  Air 80% nitrogen, 20% oxygen  Forward biased diode voltage 0.7 V  LED 1.5V  One gram of uranium gives one mega-watt day of energy  Building construction scales as the price of meat  Screws have a point, bolts are flat

7 SPIRIT Attitude-Determining Heuristics  Quantify or express all variables in numbers  Always give an answer  Work at the margin of solvable problems

8 SPIRIT Risk-Controlling Heuristics  Make small changes from previous successful solutions.  Always give yourself a chance to retreat.  Use feedback to stabilize a design.

9 SPIRIT Resource Allocation Heuristics  Allocate sufficient resources to the weak link.  Allocate resources as long as the cost of not knowing exceeds the cost of finding out.  At some point in the project, freeze the design.

10 SPIRIT Miscellaneous Heuristics  Break complex problems into smaller, more manageable pieces.  Design for a specific time frame.  Always make the minimum decision.

11 SPIRIT Problem Definition  Methods  Objective Tree  Pairwise Comparison Chart  Weighted Objectives Tree  Function-Means Tree  Functional Analysis  Requirements Matrix  Means  Literature Review  Brainstorming  User Surveys and Questionnaires  Structured Interviews

12 SPIRIT Building an Objectives Tree

13 SPIRIT Building an Objectives Tree

14 SPIRIT Functional Analysis  What does the design DO?  What functions must be performed to realize the objectives?  Put the language of the client and users into the language of the engineer.  Put things into terminology that helps to find ways to meet objectives.  Use terminology that can be used to measure how well the objectives have been met.

15 SPIRIT What are Functions?  A relationship between independent variables (inputs) and response or dependent variables. (outputs)  Mathematics:  Business Management Theory: Transformation function

16 SPIRIT Black and Glass Boxes  Like the mathematical and management models - relate the inputs to the outputs  All ins and outs must be specified  What happens to each input?  Where does the output come from?  Remove the cover to see what's going on inside. Black Box

17 SPIRIT Black Box of a Radio

18 SPIRIT Radio Glass Box (the cover has been removed)

19 SPIRIT Function-Means Tree  A graphical representation of the design's basic and secondary functions  Alternating levels of function and means  Begins the process of association of what must be done and how we might do it.  Can be used to separate and sort secondary functions associated with the design.

20 SPIRIT

21 SPIRIT Heuristics  A heuristic is anything that provides a plausible aid or direction in the solution of a problem.  Heuristics are usually unjustified and potentially fallible. is  Engineering design is the use of heuristics.  Heuristics are used to cause the best change in a poorly understood situation within the available resources.

22 SPIRIT Conceptual Design: Finding a Feasible Concept.  Break down the overall problem into subproblems.  Find solutions to each subproblem  Combine the subproblem solutions.  The aim is to start with the project definition and generate as many ways as possible of solving the problem.  Then select the most promising ideas that meet the design specification.

23 SPIRIT Conceptual Design  Methods  Performance Specification Method  Quality Function Deployment (QFD)  Morphological Chart  Means  Brainstorming  Synectics and Analogies  Benchmarking  Reverse Engineering (Dissection)

24 SPIRIT Convergent (left brain) and Divergent (right brain) Thinking