90 likes | 176 Vues
Decision Based Design Some Questions. David Kazmer University of Massachusetts Amherst. State of Engineering Design. Rational design practice is rare Modeling & analysis capabilities are poor Gross assumptions made Knowledge of constraints and preferences is typically absent
E N D
Decision Based DesignSome Questions David Kazmer University of Massachusetts Amherst
State of Engineering Design • Rational design practice is rare • Modeling & analysis capabilities are poor • Gross assumptions made • Knowledge of constraints and preferences is typically absent • Resulting designs • Designs are far from optimal • Incremental design changes fix known problems • True optimal not known or achieved
Three Questions As Framework • Should all design activities, including those that might be intuitive, e.g., brainstorming for the generation of design alternatives, be constructed under a decision theory framework? • Is Multiattribute Utility Analysis a useful method in Engineering Design? What is your approach to engineering decision making that involves multiple attributes and multiple decision makers? • What are the top research issues for developing DBD approaches to design?
Should all design activities be … under a decision theory framework? • No, such a framework can be inappropriate • Technical feasibility vs. economic feasibility • Framework acceptance • Investment required • Designer engagement and control • Availability of information • Models, constraints, preferences, expertise • Total return on investment
Designers unwilling to accept decision support/automation • Designers prefer to be engaged • Everyone suffers from not invented here • Accountability issues • Investment • Education • Time • Software Designer Engagement and Control Low High Low QFD Investment Required Optimization High DBD
“Optimal” DBD QFD Net Utility No Method Quality of Information Information Requirements • Methodology selection not trivial • Complexity of problem & availability of design options • Knowledge of different methodologies • Potential investment & profits difficult to analyze • Current state of information • Cost of information • Improved performance • Benefit of performance • All with uncertainty
Should all design activities be … under a decision theory framework? • Interpretation of “should” • Yes, decisions should be rational • No, ends do not always justify rational means Information Available Low High Low QFD Assume Result? Decision Impact High Invest in Model? DBD
Multiattribute utility analysis useful in engineering design? • Consider standard operating procedure: • Deterministic models, objectives, constraints • Use of safety factors & optimization • Little rationality or optimality • Yes, MAU useful in reasoning about design • What is functionally important? • How to trade-off attributes? • Concept through detailed design stages
Top research issues for developing DBD approaches to design? • Research • Design representation • Preference modeling • Handling of uncertainty • Development • Systems implementation • Simplification & accessibility of approaches • 8 hour seminar with worksheets