Automobile Warranty Data Analysis by Anita Rebarchak DSES-6070 HV5 Statistical Methods for Reliability Engineering Professor Ernesto Gutierrez-Miravete 8/11/2008

Objective Use warranty data collected by the manufacturer for 329 cars of the same make, model and year with a 40,000 km warranty Predict engine failure Forecast future warranty costs

Data Observations: Engine is very reliable. Most failures were very minor and accumulated no significant cost. Data only lists the first failure per engine; additional failures my have occurred over the life of the warranty

Limitations Delay in reporting failure overstates the lifetime of the failed component Data does not give component details Data does not account for multiple failures in an engine Engine is very complex and the data does not account for components relying on each other Driving environment not considered

Conclusions Wear out

Additional Analysis Normal distribution calculations in Maple Monte Carlo Simulation for MTTF Censored analysis including all 329 engines Cost analysis at MTTF