The main disadvantages or simulation are:
1. Good simulation models for complex situations can be very expensive. It is often a long, complicated develop a model. A corporate planning model, for example, may take months or even years develop.
2. Simulation does not generate optimal solutions to problems as do other quantitative analysis techniques such as economic order quantity, linear programming, or PERT. It is a trial and error approach that can produce different solutions in repeated run.
3. Managers must generate all of the conditions and constraints for solutions that they want to examine. The simulation model does not produce answers itself.
4. Each simulation model is unique. Its solutions and inferences are not usually transferable to other problems .