A comparative study of exponential distribution vs Weibull distribution in machine reliability analysis in a CMS design

The paper addresses machine reliability consideration by Weibull and exponential distribution approach in designing a cellular manufacturing system (CMS). A multi-objective mixed integer programming (MIP) model that considers machine system reliability and system cost simultaneously is presented to implement the approach. When a part has the option to be processed in alternative routes, the route with the highest system reliability can be selected by considering individual machine reliabilities along each route. A CMS design approach which selects processing routes for the part types with maximum system reliability, considering the machines along routes while optimizing system cost, will improve the overall performance of the system. The rerouting provision of the part types, integrated with the approach, will also help the user/designer to solve machine breakdown problems during processing of a part. This study offers the capability to model different failure characteristics, such as, an increasing, decreasing or constant machine failure rate. An example problem is solved to illustrate applicability of the model.