Design Process ME 250:Design Manufacturing I School of Mechanical Engineering Shanghai Jiao Tong University 1
Shanghai Jiao Tong University 1 Design Process ME 250: Design & Manufacturing I School of Mechanical Engineering
What is a Design Process? Design process knowledge A design process is a mapping Resulting Design products from customer that meet need the need need/desire to Design process paths the final product. Physics Materials Electric science motors Engineering Thermodynamics science Engineering Welding Manufacturing economics design processes Pumps (U川lman,1992) Kinematics Domain knowledge Shanghai Jiao Tong University 2
Shanghai Jiao Tong University 2 What is a Design Process? A design process is a mapping from customer need/desire to the final product. (Ullman, 1992)
The Design Process The process of designing is a complex human activity. Technical skills Other human activities ■Cognition Creativity Personal discipline Interpersonal relations Shanghai Jiao Tong University 3
Shanghai Jiao Tong University 3 The Design Process n The process of designing is a complex human activity. n Technical skills n Other human activities n Cognition n Creativity n Personal discipline n Interpersonal relations
How Can a Design Process be Structured? Divergence Transition Convergence Definition Generate solution Select most likely Select final design Prototyping concepts concept candidates Analysis Find the right problem to solve Brainstorming Pugh charts -Detailed configuration Build a working prototype -Checklists QFD Optimization .Rapid prototyping methods What problem is most -Synectics -DFX important? Manufacturing planning Is there a deeper root cause? -Morphological analysis Rough prototyping -Rough prototyping -What are the problem Brainwriting (sketch models) User feedback characteristics？ Wishful thinking Rough analysis -Testing -What are characteristics of a ldea triggers User feedback(update good solution? -Functional decomposition problem definition) What are the constraints? -Analogies QFD (ODE,2001) Shanghai Jiao Tong University 4
Shanghai Jiao Tong University 4 How Can a Design Process be Structured? (ODE, 2001)
Problem Definition Objectives Tools ●Personal Experience ●Market Research Form the design team ·Root Cause Analysis·Reverse Engineering Identify all stakeholders ·Analogies ·Case Studies ●Customer Interviews ●Patent Search Research and understand user r·Expert Interviews ·Web Search Research and understand the ●Stakeholder ●Library Search environment Interviews ●Benchmarking ●User studies ●Catalogues Research and understand the ·Semantic Inquiry ●Magazines product domain ·QFD Shanghai Jiao Tong University 5
Shanghai Jiao Tong University 5 Objectives Tools – Form the design team – Identify all stakeholders – Research and understand user – Research and understand the environment – Research and understand the product domain Personal Experience Root Cause Analysis Analogies Customer Interviews Expert Interviews Stakeholder Interviews User studies Semantic Inquiry QFD Market Research Reverse Engineering Case Studies Patent Search Web Search Library Search Benchmarking Catalogues Magazines Problem Definition
Divergence Objectives Tools ●Formal ·Checklists Generate many concepts Brainstorming ·Design Catalogues ·Morphological -Avoid details ●Functional Analysis Decomposition Raise issues that require ·Sketching ·Physical Process better specification ●Synthesis Diagrams Wishful Thinking ·Analogies -Suppress judgement ·Mind Mapping ·Iteration Shanghai Jiao Tong University 6
Shanghai Jiao Tong University 6 Divergence Objectives Tools – Generate many concepts – Avoid details – Raise issues that require better specification – Suppress judgement Formal Brainstorming Morphological Analysis Sketching Synthesis Wishful Thinking Mind Mapping Checklists Design Catalogues Functional Decomposition Physical Process Diagrams Analogies Iteration
Checklists Purpose To list all possible factors pertinent to major design activities To prevent inadvertent omission of any critical factor -To highlight critical areas for review and action To make evident a design problem or solution for use in other areas of activity Shanghai Jiao Tong University 7
Shanghai Jiao Tong University 7 Checklists n Purpose n To list all possible factors pertinent to major design activities n To prevent inadvertent omission of any critical factor n To highlight critical areas for review and action n To make evident a design problem or solution for use in other areas of activity
Conceptual Design Abstracting to identify the essential problem Establishing function structures ■ Searching for solution principles to fulfill the sub-functions Combining solution principles to fulfill the overall function Firming up into concept variants Evaluation concept variants against technical and economic criteria Shanghai Jiao Tong University 8
Shanghai Jiao Tong University 8 Conceptual Design n Abstracting to identify the essential problem n Establishing function structures n Searching for solution principles to fulfill the sub-functions n Combining solution principles to fulfill the overall function n Firming up into concept variants n Evaluation concept variants against technical and economic criteria
Abstracting Abstracting means to ignore what is particular and incidental and emphasize what is general and essential Shanghai Jiao Tong University 9
Shanghai Jiao Tong University 9 Abstracting n Abstracting means to ignore what is particular and incidental and emphasize what is general and essential
Establishing Structures Establishing a function structure by breaking down the overall function into sub-functions. The clear definition of existing sub-systems facilitates the search for solutions by dealing with each sub-function component separately. Determine logical functional relationships with the search for essential functions. Logical relationships are derived directly from the corresponding of the problem specification. Function structures should be kept as simple as possible to so as to lead to simple and economical solutions. Shanghai Jiao Tong University 10
Shanghai Jiao Tong University 10 Establishing Structures n Establishing a function structure by breaking down the overall function into sub-functions. n The clear definition of existing sub-systems facilitates the search for solutions by dealing with each sub-function component separately. n Determine logical functional relationships with the search for essential functions. n Logical relationships are derived directly from the corresponding of the problem specification. n Function structures should be kept as simple as possible to so as to lead to simple and economical solutions