The Design Process Involves Creativity

1. The Design Process Involves Creativity Conceptual design, embodiment design and detail design are the three activities that separate the engineering design processes from the problem solving processes. Problem solving is done by nearly everyone, nearly every day. A problem, like ``my car won't start'' or ``how can we increase our market share'' can be solved by following the problem solving steps. However, these examples are not problems in engineering design because there is no conceptual design, no embodiment design, and no detail design. cf. Engineering Design Processes, Problem Solving &Creativity Don L. Dekker Rose-Hulman Institute of Technology

2. Embodiment Design Converts Concepts into Reality Embodiment design consists of preliminary layouts and configurations, selecting the most desirable preliminary layouts and refining and evaluating against technical and economic criteria.

3. Embodiment design requires planning Objectives: • Define the overall geometric layout. • Define the forms and composition of all components. • Define the required production procedure. Deliverables: Specific scaled drawings Material Selection criteria Production process and schedule

4. There are three basic rules all design should follow: • Clarity - Identify functions and mathematical relationships • Simplicity - Fewer parts = lower costs • Safety - Avoid need of warning labels.

5. Second stage of the design process involves details • Configuration design establishes the shape and general dimensions of components. • Identify design risks, cf. p.223 text.  Parametric design identifies the design variables that can be controlled. - Objective is to improve the robustness of the design.

6. There are three ways to improve robustness: • Improve the design concept of the function to be fixed • Change the value of a critical parameter • Systematically optimize the design variables

7. Pugh Analysis Aids Design Decisions It provides a technique for choosing among design alternatives.  In the 1980s Stuart Pugh developed the methodology at the University of Strathclyde in Glasgow, Scotland. It is often called the Pugh Concept Selection Matrix.

8. There is a systematic way of selecting between alternatives • Identify relevant user requirements; develop engineering specifications for those requirements.  Develop weights for each of the requirements. •Generate several viable design concepts. • Rank the concepts using Pugh analysis. • Synthesize the best elements of each initial concept into a final optimal concept. • Iterate until a clearly superior concept emerges. Ref: “Getting Better Results in Design Concept Selection” D. Warburton, Medical Device and Diagnostic Industry January 2004

9. Selecting criteria can be based on QFD (HOQ) • List 15 or 20 criteria based on QFD and functional analysis.  Develop concepts • Formulate the decision matrix  Select one concept as a datum (i.e., baseline).

10. Decision Matrix Helps Organize Concepts

11. Potable Dialysis Machine Design is an example for Pugh Analysis

12. Add The Scores And Evaluate

13. If 2 (or more) concepts are equal – reevaluate requirements and concepts

14. Pugh Technique Accomplishes Several Objectives: •It compelled the design team to review the user requirements in detail and to understand how the requirements apply to the design. • It compelled the team to look beyond the obvious first concept and to fully explore a wider range of concepts. • It provided an objective way to evaluate those concepts. Ref: “Getting Better Results in Design Concept Selection” D. Warburton, Medical Device and Diagnostic Industry January 2004

15. The Pugh concept provides a concise, auditable document for the product’s design history file. • This document demonstrates that the team used a process to achieve a result, and those results can be reviewed and understood. • Pugh analysis also provides a clear format for presenting information and an evaluation and ranking process. • Finally, it provides an easily understandable deliverable for the design history file to prove that the process has been completed. Ref: “Getting Better Results in Design Concept Selection” D. Warburton, Medical Device and Diagnostic Industry January 2004