The Operations Manager of a Body and Paint Shop Has

Essay

The operations manager of a body and paint shop has five cars to schedule for repair. He would like to minimize the throughput time (makespan) to complete all work on these cars. Each car requires body work prior to painting. The estimates of the times required to do the body and paint work on each are as follows:
$$\begin{array} { | c | c | c | } \hline \text { Car } & \begin{array} { c } \text { Body Work } \\\text { (Hours) }\end{array} & \text { Paint (Hours) } \\\hline \text { A } & 8 & 7 \\\hline \text { B } & 9 & 4 \\\hline \text { C } & 7 & 9 \\\hline \text { D } & 3 & 4 \\\hline \text { E } & 12 & 5 \\\hline\end{array}$$
a. Chart the progress of these five jobs through the two centers on the basis of the arbitrary order
A→B→C→D→E.
b. After how many hours will all jobs be completed?
$$\begin{array} { | l | l | l | l | l | l | l | l | l | l | l | } \hline \text { Body Work } & & & & & & & & & & \\\hline \text { Paint } & & & & & & & & & & \\\hline & 5 & 10 & 15 & 20 & 25 & 30 & 35 & 40 & 45 & 50 \\\hline\end{array}$$
c. Use Johnson's rule to sequence these five jobs for minimum total duration. Show your work in
determining the job sequence.
d. The optimal sequence is __________.
e. Chart the progress of the five jobs in this optimal sequence.
f. After how many hours will all jobs be completed?