$CAP{T}_t$

Capacity available in time units in the period t.

$D_{it}$

Demand for the item i during the period t.

$P{T}_{it}$

Time required for processing the item i.

$S{T}_i$

Time required for setting up the production for the item i.

Definition of Variables

$X{P}_{it}$

Number of items i to be produced in the period t.

$XIN{V}_{it}$

Number of items i carried as inventory to be produced during the period t.

$XB{O}_{it}$

Number of item i that will be backordered from the period t.

$Y{S}_{it}$

Binary setup variable.