I. Interactive input
All the information required in this model is supplied through different questions asked by FLEXPLAN:

User Input UNIT
Number of processes  
Number of periods  
Number of Chemicals  
Number of Alternate Production Schemes  
Number of markets  
Interest rate  
Tax rate  
Project life time years
Lengrth of time periods years
Index set of all production schemes  
Limit on investment $/year
Process availability per period  
Main product for each process  
Limit on the number of expansions  
Working capital factor  
Exisiting capacities Lb/year
Salvage value factor  
Lower and upper bound on expansion LB/year
Mass balance coeffients*  
Variable investment coefficient $/Lb-yr
Fixed investment coefficient $/yr
Operating expenses per unit of main product $/LB
Cost for purchase of one unit of chemical $/LB
Purchase lower and upper bounds LB/yr
Sales lower and upper bounds LB/yr
Product Rate Coefficients