A labor-dependent task is one that can be sped up by using additional operators. In particular, a labor-dependent task is one whose elapsed duration is inversely proportional to the number of operators performing it. Labor-dependent process time for a process is the total time it would take 1 operator to perform the labor-dependent tasks that the process models.

A labor-independent task is one that is not labor-dependent. Labor-independent process time for a given process is the total elapsed duration of the labor-independent tasks that the process models.