THE OPTIMAL OPERATION OF MIXED PRODUCTION FACILITIES - A GENERAL FORMULATION AND SOME APPROACHES FOR THE SOLUTION

This paper extends the concept of a ''resource-task network'', describ ed by Pantelides, to provide a unified mathematical formulation of the problem of determining the optimal operating conditions of a mixed pr oduction facility, comprising multipurpose plant for both batch and co ntinuous operations. The formulation uses a variable event-time sequen ce common to all system events. This yields a large mixed integer nonl inear programming problem. For batch processes with fixed recipes the problem is linear and can be solved by existing techniques. Alternativ e approaches for solving the general problem are discussed, and some p reliminary numerical results are presented.