麻省理工学院：《Robust System Design》Context of robust Design

Context of robust design Don clausing C Don Clausing 1998

Context of Robust Design Don Clausing Fig. 1 © Don Clausing 1998

Case study An automatic document handler(adh) was developed at the ss level. When integrated into the total system there were many new problems. The TQM Problem Solving Process was used, and many problems were solved. however. at the Field readiness Test (frt) before entering production the reliability was 15X worse than acceptable Fig. 2 C Don Clausing 1998

Case study An automatic document handler (ADH) was developed at the SS level. When integrated into the total system there were many new problems. The TQM Problem Solving Process was used, and many problems were solved. However, at the Field Readiness Test (FRT) before entering production the reliability was 15X worse than acceptable. Fig. 2 © Don Clausing 1998

Case study questions What should they do next? the same dysfunctional path re to avoid What should be done in the futu What is the fundamental problem? Fig. 3 C Don Clausing 1998

Case study questions • What should they do next? • What should be done in the future to avoid the same dysfunctional path? • What is the fundamental problem? Fig. 3 © Don Clausing 1998

Bomb alert Concept Design > Ready> Produce FRT Technology Stream Too much dependence on reactive improvement 4 C Don Clausing 1998

Bomb alert! Technology Stream Concept Design Ready Produce FRT Too much dependence on reactive improvement Fig. 4 © Don Clausing 1998

Improvement to avoid bombs TSRCI I IMPROVE SSRC MENT RC I PPRC TECHNOLOGY PROACTIVE REACTIVE IMPROVEMENT MPROVEMENT R: requirements C: concept TS: total system SS: subsystem PP: piece parts C Don Clausing 1998

Improvement to avoid bombs RC I RC I RC I RC I IMPROVE MENT TECHNOLOGY TS SS PP I – PROACTIVE IMPROVEMENT REACTIVE IMPROVEMENT R: requirements C: concept TS: total system SS: subsystem PP: piece parts Fig. 5 © Don Clausing 1998

Proactive improvement Yea, we think that proactive is good Fig. 6 C Don Clausing 1998

Proactive improvement Yea, we think that proactive is good! Fig. 6 © Don Clausing 1998

What is wrong here? Concept> design> Read Produce FRT ceehneloay stream C Don Clausing 1998

What is wrong here? Technology Stream Concept Design Ready Produce FRT Fig. 7 © Don Clausing 1998

Rework -how much is enough? R Design Complete 8. Producti n Buld/estFⅸ Buld/estFⅸ Build/est/FⅸX Produce Build/Test/Fix Fig. 8 C Don Clausing 1998

Rework – how much is enough? Design Complete Ready for Production Produce Build/Test/Fix Build/Test/Fix Build/Test/Fix Build/Test/Fix Fig. 8 © Don Clausing 1998

Build/test/fix-why Reactive problem solving Too little- limited scope of solutions Too late Design contains many unsolved problems Biggest problem is lack of robustness System works well in favorable conditions But is sensitive to noises -unfavorable conditions that inevitably occur 9 C Don Clausing 1998

Build/test/fix – why? • Reactive problem solving – Too little – limited scope of solutions – Too late • Design contains many unsolved problems • Biggest problem is lack of robustness – System works well in favorable conditions – But is sensitive to noises – unfavorable conditions that inevitably occur Fig. 9 © Don Clausing 1998

Proactive problem solving Must shift from emphasis on build/test/fix Must address effects of noises Erratic performance Leads to delusionary problem solving chases problem from one failure mode to another Fg.10 C Don Clausing 1998

Proactive problem solving • Must shift from emphasis on build/test/fix • Must address effects of noises – Erratic performance – Leads to delusionary problem solving; chases problem from one failure mode to another Fig. 10 © Don Clausing 1998