Production scheduling in almost continuous time

We present a large-scale production scheduling problem where each order is unique and the processing time for an operation can be close to the size of a time period. Because modeling the problem as a multiprocessor flowshop results in a computationally intractable formulation, we cast the problem in production planning terms and extract a production schedule from the solution. To solve our model, we introduce the notion of ‘almost continuous time’ and show how to obtain good solutions to large problems efficiently.