Abstract:
Linear programming has proved to be an efficient tool for solving complex planning problems, especially in pot plant nurseries.
If the system is put into practice often, it will quickly be seen that the actual buildingup of the LPmatrix can be an extensive task.
It is therefore of great importance to work out a preprogramme from which the LPmatrix can be built up automatically.
In a normal pot plant nursery it is not unusal to have 30–50 production alternatives (columns) and 150–200 constraints (rows). The construction of an LPmatrix of these dimensions can easily be very extensive, and it should at the same time also be reasonably simple to make minor adjustments without having to calculate the gross margins for the different production alternatives.
The printout from a feasible LP solution cannot be said to be of any great benefit from the grower's view point.
The LP solution consists of a printout of the optimal values, a printout of values of production alternatives and their reduced costs, and a printout of constraints with activity, slack activity and dual activity (shadow prices). These figures must be adapted so as to be easy to work with.
This can be done manually, but easily becomes timeconsuming when put into practice.
It is therefore of great importance to have a programme, which can "translate" the LP solution into information, which is clear and understood by the grower.
