Chapter 2 Knowledge need to know before start a project Method of generating the concept Method of decision making Review the worth of a project Communication methods
Methods of generating concepts Brainstorming as a source of ideas Using 6-3-5 method as a source of ideas The use of analogies in design Finding ideas in reference books and trade journal using expert to help generate concept
The individual designer: A model of human information procession
Type of knowledge Type of memory General knowledge Domain-specific knowledge Procedure knowledge Type of memory Short term memory Long term memory
Analogy Umbrella VS. removal of urinary calculi
Nature system Velcro Fastener
Methods of decision making Decision matrix Step 1: choose the criteria for comparison. Step 2: Develop Relative importance weightings Step 3: Select Relative Importance Weightings Step 4: Evaluate Alternatives . Step 5 Compute Satisfaction
Decision matrix Criteria (requirement s or specification importance Alternative 1 Alternative 2 Alternative 3 Criterion 1 xx Evaluation of alternate 1 using criteria 1 Evaluation of alternate 2 using criteria 1 ……. Criterion 2 yy Evaluation of alternate 1 using criteria 2 Evaluation of alternate 2 using criteria 2 …….. ……… Satisfaction Score for Alternative 1
Example: Using the decision matrix:
Evaluation Based on advanced Decision matrix Step 1: choose the criteria for comparison. Step 2: Develop Relative importance weightings Step 3: Select Relative Importance Weightings Step 4: Evaluate Alternatives . Step 5 Compute Satisfaction Satisfaction =Σ(belief*importance weighting)
Believe Belief=confidence placed on an alternative’s ability to meet a target set by a criterion, requirement, or specification, base on current knowledge.
Belief=p(k)*p(c)+(1-p(k))*(1-p(c))
Example Criteria Importance Alternative Linear guide Voice coil 1 Can support the optical system 50 0.77 0.3 2 Move fast 20 0.5 0.9 3 Can correct the light abbreviation 0.8 4 Can Do small adjustment 10 0.6 Satisfaction 62 55
Making a portfolio decision SA: strongly agree A; Agree N: neutral D: disagree SD: Strongly disagree VC: Very certain C: Certain N: Neutral U: uncertain VU: very uncertain
Review the worth of a project Before beginning a project Is there a good potential return on investment? Does the new product or improvement fit the company image? Does it fit the distribution channels? Is there sufficient production capacity in-house or with known vendors? What will the project cost?
Communication methods Design Record-design note book Documents communicating with management-design reviews Documents communicating the final design -drawing of components and assemblies -written documentation to guide manufacturing, assembly, inspection, installation, maintenance, retirement and quality control