Luke Steffie owns a balloon store and must fill balloons with helium and assemble them into certain configurations today for six major parties. His six customer jobs all need to use the same helium tank (that is, the single-resource processor). Each job consists of up to one-hundred balloons. Luke is wondering the best way to sequence these jobs. Client (job) number five is his top customer. Luke’s assistant store manager, Cindy Cheshire, wants to process them in sequential order (i.e., 1, 2, 3, 4, 5, and 6). Because the balloons lose air quickly, the company waits until the day of the parties to fill them. The workload is hectic. Business is booming and growing about 15 percent per year in their store location. The job processing time estimates are as follows: 

Case Questions for Discussion: 

1. Compute the average flow time, lateness, and tardiness for this group of jobs using Ms. Cheshire’s sequential order of 1 (first), 2, 3, 4, 5, and 6 (last). 

2. In what order would the jobs be processed using the SPT rule? Compute the average flow time, lateness, and tardiness for this group of jobs.

3. Compare the answers in Questions 1 and 2. 

4. What are your short-term recommendations for this set of six jobs? Explain your reasoning. 

5. What are your long-term recommendations with respect to sequencing jobs at Luke’s store? Explain your reasoning. 

Transcribed Image Text:

Job Processing time (min.) Due dates (6 a.m. to midnight in minutes from opening) 1 240 240 2 130 360 3 210 480 90 240 5 170 720 6 165 780