The inventory problem

Describes the problem and gives the path to the files.

The problem is to build steel coils from slabs that are available in a work-in-progress inventory of semi-finished products. The assumption is that there is no limitation in the number of slabs that can be requested, but only a finite number of slab sizes is available (sizes 12, 14, 17, 18, 19, 20, 23, 24, 25, 26, 27, 28, 29, 30, 32, 35, 39, 42, 43, 44…). The problem is to select a number of slabs to build the coil orders, and to satisfy the following constraints:

• Each coil order requires a specific process to be built from a slab. This process is encoded by a color.

• A coil order can be built from only one slab.

• Several coil orders can be built from the same slab. But a slab can be used to produce at most two different ‘colors’ of coils.

• The sum of the sizes of each coil order built from a slab must not exceed the slab size.

Where to find the files

You will work with the steel mill example, supplied as the steelmill example at the following location:

<Install_dir>\opl\examples\opl\steelmill

where <Install_dir> is your installation directory.

Data for the model steelmill.mod is contained in the file steelmill.dat.