A method for the design of a production process determines the assignment of operations to one or more machines where each machine has a given capacity for installing multiple parts to items in an assembly line. A list of parts of each different item to be assembled is prepared. The production demand for each different item is determined. An algorithm based on the parts list and the production demand is applied to determine an assignment of operations to the one or more machines so that total setup and processing cost is minimized. Operations are assigned to the one or more machines based on the application of the algorithm.