In CP Optimizer, piecewise linear functions are typically used to model a known function of time, such as the cost incurred for completing an activity after a known date t (see Expressions over Interval Variables).

A piecewise linear function  F(t) is defined by a tuple F = piecewise(S, T, t0, v0) where:

In CP Optimizer, stepwise functions are typically used to model the efficiency of a resource over time (see Intensity and size and forbidden values). A stepwise function is a special case of piecewise linear function where all slopes are equal to 0 and the domain and image of F are integer. A stepwise function F(t) is defined by a tuple F = stepwise(V, T) where: