Consider a process that consists of three steps $1,2$ and $3.$ Steps $1$ and $2$ are each equipped by a single machine. Step $3$ is performed by a single worker. Each of the process steps works on one unit of work at a time, but must complete a $$set up$$ between production batches. The required processing times and set$-$up times at each of the steps are listed below. There is unlimited space for buffer inventory between these steps. The system has an unlimited supply of work available to be performed $($i$.$e$.,$ demand exceeds capacity$).$

Process step Set up time Activity time

$150$ min $2$ min$/$unit

$2120$ min $1$ min$/$unit

$305$ min$/$