A new surgical facility called Cut & Sew is opening in neighborhoods throughout the United States. They are job shops that handle a variety of outpatient surgical procedures. Their process is set up so that one doctor cuts and another sews. They have five patients to sequence for tomorrow. Since the weather forecast is for a warm and sunny day, they would also like to play golf tomorrow. They want to sequence their patients with the objective of minimizing the time from the beginning of the first job until the finish of the last job. The patients and estimated times are as follows:
$\begin{array}{|c|c|c|}
\hline \text { Patient } & \text { Cut Time (hours) } & \text { Sew Time (hours) } \
\hline \text { A } & 2.3 & 2.8 \
\hline \text { B } & 2.5 & 3.0 \
\hline \text { C } & 2.0 & 1.5 \
\hline \text { D } & 0.6 & 1.0 \
\hline \text { E } & 3.6 & 2.6 \
\hline
\end{array}$
-Using Johnson's rule to sequence the patients, and if your uncle is patient B, he will be finished with surgery in _____.
A) less than or equal to 5 hours
B) more than 5 but less than or equal to 10 hours
C) more than 10 but less than or equal to 15 hours
D) more than 15 but less than or equal to 20 hours

Question

A new surgical facility called Cut & Sew is opening in neighborhoods throughout the United States. They are job shops that handle a variety of outpatient surgical procedures. Their process is set up so that one doctor cuts and another sews. They have five patients to sequence for tomorrow. Since the weather forecast is for a warm and sunny day, they would also like to play golf tomorrow. They want to sequence their patients with the objective of minimizing the time from the beginning of the first job until the finish of the last job. The patients and estimated times are as follows:
 $\begin{array}{|c|c|c|}
\hline \text { Patient } & \text { Cut Time (hours) } & \text { Sew Time (hours) } \
\hline \text { A } & 2.3 & 2.8 \
\hline \text { B } & 2.5 & 3.0 \
\hline \text { C } & 2.0 & 1.5 \
\hline \text { D } & 0.6 & 1.0 \
\hline \text { E } & 3.6 & 2.6 \
\hline
\end{array}$
-Using Johnson's rule to sequence the patients, and if your uncle is patient B, he will be finished with surgery in _____.
A) less than or equal to 5 hours
B) more than 5 but less than or equal to 10 hours
C) more than 10 but less than or equal to 15 hours
D) more than 15 but less than or equal to 20 hours

Quizplus · Accepted Answer

Johnson's rule for scheduling jobs in a two-machine system involves sequencing the jobs in such a way that the job with the shortest processing time on either machine is scheduled next, with the condition that if that shortest time is on the first machine, the job is scheduled as early as possible, and if on the second machine, as late as possible. Applying Johnson's rule to the given data:1. D (0.6 on Cut) - earliest because it has the shortest cut time.2. C (1.5 on Sew) - next shortest overall time, and it's on the Sew machine, so it goes towards the end but before any other job scheduled by Sew time.3. A (2.3 on Cut) - next shortest cut time, goes after D.4. E (2.6 on Sew) - next shortest sew time, goes before C because C was the first scheduled by shortest Sew time.5. B (2.5 on Cut) - last remaining job, goes after A.The sequence is D, A, B, E, C. To find out when patient B (your uncle) will be finished, we calculate the cumulative time up to and including his surgery:- D's Cut + Sew = 0.6 + 1.0 = 1.6 hours- A's Cut + Sew = 2.3 + 2.8 = 5.1 hours- B's Cut + Sew = 2.5 + 3.0 = 5.5 hoursCumulative time when B is finished = 1.6 (D) + 5.1 (A) + 5.5 (B) = 12.2 hoursTherefore, your uncle will be finished with surgery in more than 10 but less than or equal to 15 hours.

A New Surgical Facility Called Cut & Sew Is Opening