Solve

 

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Solve

This screen is used to solve the constructed problem by calling AMPL, once it has finished solving summary reports are generated and added to the directory tree. the solution of how much to cut and when, as well as replant and transfer information is stored in the problem file once it is saved, this information if desired can be found by opening the problem file with Microsoft Access.

To open the problem file in Access just double click the file in a browser window or open Access and choose open from the file menu, then find the appropriate file.

Solve Status

The Solve status is show at the top of the screen. It shows whether the current model has been solved, and if a feasible solution was found. if a feasible solution was not found then the message will say either "Infeasible" or "Unbounded".

If the Solve status has a value of "Infeasible" then the model has been overly constrained so that there is no possible solution possible that would satisfy all of the constraints.

If the Solve status has a value of "Unbounded" then it would be possible to make the objective function infinite. A possible cause of an unbounded model is if you are able to replant from bareland and there is no additional constraint limiting and amount of land that can be purchased.

Objective Function Value

If the objective is to maximise net present value, then the objective function value is the amount of discounted cashflow summed over the length of time stated in the objective function definition.

If the objective is to maximise yield, then the objective function value is the amount of discounted clearfell volume produced over the length of time stated in the objective function definition.

 

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