Prototype fleet optimization model

Product development in the automotive industry is a complex process that involves extensive testing of components, subsystems, systems and full vehicles. A fleet of unique individually manufactured vehicles must be built and scheduled amongst different major system activities to be used in comprehensive testing programs. In this paper we present a multi-stage mathematical programming model, set covering plus scheduling, that has been used to restructure the development of the prototype fleet and the assignment of tests to specific vehicles. A basic version of the model implemented on a complex vehicle program produced a 25% reduction in fleet size as compared to the forecast originally made by the company. In addition, the model was the driver for the restructuring of the prototype planning process. In presenting this model, we will describe: (a) the model development process including structuring of the input and output to meet customer needs, (b) model structure, (c) keys to implementation success, and (d) the system's overall impact on the prototype planning process.