Objective

The objective is to minimize the following function:

\[  \begin{split}  \Variable{TotalCost} = \underset { \text {type} \in \text {TYPES}}{\sum _{\text {period} \in \text {PERIODS},}} ( & \Argument{unit\_ cost[type]} \cdot \Argument{length[period]} \cdot \Variable{NumWorking[period,type]} \\ + & \Argument{excess\_ cost[type]} \cdot \Argument{length[period]} \cdot \Variable{Excess[period,type]} \\ + & \Argument{startup\_ cost[type]} \cdot \Variable{NumStartup[period,type]}) \\ \end{split}  \]