Consider a process described by the following process flow diagram:

A process flow diagram

Note that it is the same machine $($machine $3)$ used by the same person $($Dorothee$)$ to do tasks $3$ and task $4.$ The task times are shown in the table below:

Task Time $($in minutes per unit$)$

$14$

$25$

$33$

$43$

The task times are constant, there is no variability.