A sequential ordering problem in automotive paint shops

In paint shops in the automotive industry, a change of colours between two consecutive cars causes sequence-dependent set-up costs. Often, selectivity banks are used as storage and retrieval systems to create colour-oriented batches of cars before the paint application in order to reduce set-up costs. The efficient control of those selectivity banks is considered a major problem of operating paint shop systems. A branch&bound approach for the colour batching process is presented. Some computational results obtained with the approach are described. An additional focus is to outline the characteristics of parts of the colour-batching problem in selectivity banks as a sequential ordering problem.