A unified process flow management system (UPFMS) that combines a CIM system, process/device simulator, CAD system, and manufacturing line schedular has been developed. This new system uses a new language called PDL to describe the process flow as common information for all systems. The UPFMS consists of the flow edit section, the flow inspection section, and several types of interface programs to make it suitable for use with other systems. The process flow data described using the PDL in the UPFMS provides data for controlling lots in CIM system. If modification of the process flow data in the CIM system is required, the process flow data is returned to the UPFMS and modified with inspection using a knowledge data base. Then, the error-free process flow data is sent back to the CIM system for Processes after flow inspection. Moreover, the UPFMS, with the new language PDL, generates recipe data for the equipment using an interface program, and recipe data is input to several types of equipment. Furthermore, the PDL process flow data can also be used as input data for the manufacturing line scheduler using another interface program. Mask and layout data in a CAD system can be exchanged among process/device simulators by using the UPFMS, and thus two-dimensional device characteristics. Spice paramenters can be also to be created. The UPFMS combines with CIM system, process/device simulator, CAD system, and the manufacturing line scheduler using common information, PDL. The process flow data created in the UPFMS can be used to control all systems from the simulation to CIM system as common data.