Some cost models of the made-to-order production situation incorporate learning and production rate as cost factors. The model developed in this paper is more detailed than the previous efforts. Here the build up of work-in-process to a steady state is explicitly modelled. Likewise, the decrease in work-in-process at the end of the programme is modelled. In this paper, we minimize cost to determine the appropriate task sizes and sequence of resources to allocate to crews of assembly workers. Crew cycle times are also determined.