Application of a mathematical model to an intermediate- to long-term real-world steel production planning problem based on standard software

In this paper, a case study accomplished for the production planning of a German steel producer is presented. This includes the description of a lot-sizing problem and a related simple mathematical model formulated in order to meet the requirements for the mid- to long-term planning of the steel producer. Both the mathematical model and the representation of the results had to be implemented based on standard software products, namely the 'ILOG OPL-Studio' from IBM and the 'Advanced Planner and Optimizer' (APO) from SAP. The main focus is on the model and its implementation. That is, we show that a real-world problem can be solved by means of a simple mathematical model and standard software products reducing the individual programming effort. [Submitted 02 February 2009; Revised 06 November 2009, 16 February 2009; Accepted 23 February 2010]