We recommended the use of multi-dimensional modelling platform AIMMS for a succinct representation of the mathematical model, together with interactive and visual user views to aid sense checking and interpretation of results.
We also recommended the use of the Cplex solver, which has an excellent track record for fast solution of large and complex integer linear programs.
We used these to develop the OPTI-WRMP model and carried out a pilot study on a region characterised by multiple water resource zones, interzonal transfers, and complex interdependencies.
The new model is able to represent an extremely large and complex set of water resources options. It can quickly identify an optimal strategic plan to balance project supply and demand across a range of 10, 25 and 50 year planning scenarios. It has also delivered a reduction in solution times from more than 24 hours to less than 10 minutes.