Silicon Prairie Initiative on Robotics in Information Technology The Engineering Design Process

Engineers and Scientists Science and mathematics is about understanding and describing the world. Engineering is about using this understanding to create new objects and devices for the practical benefit of humans and society. Science uses the “scientific method” Engineering uses the “design process”

Engineers and Scientists The Scientific Method Observe some aspect of the universe Formulate a hypothesis consistent with observation Use the hypothesis to make predictions Test the predictions with experiments Modify the hypothesis in light of results Repeat testing until no discrepancies between theory and experiment

Engineers and Scientists Engineering Design Process Identify the problem or design objective Define goals and identify constraints Research and gather information Create potential solutions Analyze the viability of the solutions Choose the most appropriate solution Implement the solution Test and evaluate the design Repeat ALL steps as necessary

References Definition of the Engineering Method; Billy Vaughn Koen; American Society for Engineering Education; 1985; ISBN: 0-87823-101-3 Discussion of The Method; Billy Vaughn Koen; Oxford University Press; 2003; ISBN: 0-19-515599-8 Strategies for Creative Problem Solving; H. Scot Fogler and Steven E. LeBlanc; Prentice-Hall; 1995; ISBN: 0-13-179318-7

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. Engineering design is the use of heuristics. Heuristics are used to cause the best change in a poorly understood situation within the available resources.

Engineering Design Process

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

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

Problem Definition Methods Means 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

Building an Objectives Tree

Building an Objectives Tree

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.

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

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

Black Box of a Radio

Radio Glass Box (the cover has been removed)

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.

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. Engineering design is the use of heuristics. Heuristics are used to cause the best change in a poorly understood situation within the available resources.

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.

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

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