5.2 SUMMARY

The problem faced by forestry planners and managers was defined. The challenge was to determining whether the planting and growing of a forest could be achieved in a way that enabled future harvesting at a sustainable rate. The sustainable size and rate of harvesting were to be calculated. Through a series of clearly defined steps, basic modules were built and tested. These were integrated into a new model and functionality was demonstrated.

Each of the modules was converted to an array version and equivalent functionality demonstrated. Each of the modules was then integrated into an array model which combined the functioning of three previously separate modules. Again it was demonstrated that the functionality was identical to previous versions. We now have the basis for creating array models for analysing a range of ageing problems.

In the next chapter we address the challenge of verifying the functioning of modules and models. We examine the tests needed to assure verification. We also consider the validation challenge. That is, we examine what is needed to provide models that are sufficient representations of the real world to be valuable.