Modify the multiple project-scheduling model in Example 15.4 so that each project has its own due…

Modify the multiple project-scheduling model in Example 15.4 so that each project has its own due date. These due dates are listed in the file P15_13.xlsx. Assume no revenue is earned unless a project is completed by its due date. Assuming that the objective is still to maximize total revenue, when should each project be started?

Example 15.4

SCHEDULING PROJECTS AT TIMBURTON

Timburton Construction has 10 projects that it can (if desired) complete within the next 10 months. Each project earns a certain revenue when it is completed, but only if it is completed within the next 10 months. Otherwise, the project earns no revenue. The number of workers needed each month, the number of months needed to complete each project, and the revenue earned from each completed project are listed in Table 15.7. We assume that after the company begins working on a project, it must work on the project during consecutive months until the project is completed. Timburton has 220 workers available each month. How can it maximize the revenue earned during the next 10 months? Objective To find starting times for the projects so that total revenue is maximized and worker utilization each month is no greater than worker availability.