Purchasing .fabrication assembly distribution figure 1.1: multi-level manufacturing system for make-to-order products specific resources of a type, i.e., a certain machine or a single worker, the determination of the sequence operations are processed on a ma chine, and the assignment of start and finish times to operations. we will modify this framework to be specifically suited for multi level make-to-order manufacturing systems. we assume that the facil ity design issue is settled, i.e., the location and the layout of the facility as well as the capacity ofthe three main resource types of the company are determined. these resource types are the engineering department, the fabrication department, and the assembly department. the engineering department is concerned with the construction of new products as well as the modification and customization of ex isting products. this entails the generation of engineering documents such as blue prints for manufacturing. the capacity of the engineering department is determined by the the count and qualification of engi neers and by the availability of construction devices such as computer aided design (cad) systems etc.