高分机械 research proposal.docx

Research ProposalEarly inference on reliability of automotive components by using past data and technical information1Background1.1SignificanceWhen a new product is the result of design or process improvements introduced in its predecessors, then the past failure data and the expert technical knowledge constitute a valuable source of information that can lead to a more accurate reliability estimate of the upgraded product. This proposalintroduces a Bayesian procedure to formalize the prior information available about the failure probability of an upgraded automotive component. The elicitation process makes use of the failure data of the past product, the designer information on the effectiveness of planned design/process modifications, information on actual working conditions of the upgraded component and, for outsourced components, technical knowledge on the effect of possible cost reductions. By using the proposed procedure, more accurate estimates of the failure probability can arise. The number of failed items in a future population of vehicles is also predicted to measure the effect of a possible extension of the warranty period. Finally, the proposed procedure was applied to a case study and its feasibility in supporting reliability estimation is illustrated.The automotivemanufacturersperformreliabilityanalysesontheirnewproductsinordertoverifytheattainmentofagiven reliability targetataspecifiedperiodt0 (e.g., thewarrantyperiodorthefulllife).Thisaimsbothtosatisfytheexpectationsoftheir customersandtocontroltherepair/substitutioncostsduringthewarrantyperiod.Ifthetargetisnotachieved,thentheproduct reliability hastobetimelyimprovedbyidentifyingthemainfailuremodesandintroducingdesignand/orprocessmodifications capable toremovethem. Main reliabilityevaluationsaregenerallyperformedatfourspecificmilestones,whichoccurduringthedevelopmentand after thecommercializationofanewcarmodel.Inparticular: Atthebeginningoftheproductdevelopmentprocess(PDP)tovalidatethechoicesmadeforp