A Print Shop Has Five Large Commercial Printing Jobs to Finish

Essay

A print shop has five large commercial printing jobs to finish. They are trying to decide whether to use the shortest processing time SPT) or the first-come first-served (FCFS) sequencing rule. Data on estimated processing time in hours) and time to promised completion in (hours) is as follows jobs shown in (order of arrival):
$$\begin{array} { c c c } \text { Job } & \text { Processing time } & \text { Thme to promised completion } \\\text { A } & 4 & 8 \\\text { B } & 9 & 30 \\\text { C } & 5 & 17 \\\text { D } & 8 & 8 \\\text { E } & 11 & 12\end{array}$$
a. What is the average flow time in hours using the FCFS rule?
b. What is the average job lateness in hours using the FCFS rule?
c. What is the average flow time in hours using the SPT rule?
d. What is the average job lateness in hours using the SPT rule?