FLEXPLAN is a program developed for the long-term planning of chemical process networks with dedicated and flexible plants. It is formulated as a multiperiod MILP model according to Leon Norton and Ignacio E. Grossmann (1994).

FLEXPLAN is assumed that a network of processes and chemicals and their interconnectivity is given. This network consists of existing processes as well as potential new processes and chemicals. The processes are either dedicated or flexible, and operate either continuously or in batch mode. Flexibility extends to not only different main products, but also different raw materials, or sources of raw materials. Forecasts for raw material availabilities, product demands, and chemical pricing for number of time periods in a long range planning horizon are also given. In addition, investment and operating costs for each existing or potentially new process are given.

The problem is to maximize the net present value of the network over a multiperiod planning horizon by determining the best

• set of expansion policies for new and existing processes

• process operating rates for each time period

• sales and purchases for each time period

This interface is written in language C and it is implemented on Windows NT, IBM RS6000, HP and SUN (SunOS and Solaris) workstations. The way this interface works is through the use of different menus; it is flexible and easy to use. Given the data of the problem, FLEXPLAN creates a new GAMS file containing the model equations and optimizes the problem using the subroutine SCICONIC, CPLEX or OSL.

FLEXPLAN has been developed by Arzu Türkay under the supervision of Ignacio E.Grossmann.

References for FLEXPLAN:

• Norton L.C. and I. E. Grossmann, MILP Multiperiod Model for Capacity Expansion in Flexible Continuous and Batch Processes , Ind. Eng. Chem. Res., Vol. 33, No.1, 1994.

• Türkay, Arzu, Guidelines for FLEXPLAN Interface, Carnegie Mellon University, Engineering Design Research Center,Pittsburgh, PA.

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