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(a)
Interpretation:
The best sequence in terms of the average flow time:
Concept Introduction:
(a)
Explanation of Solution
Given information:
The table below contains the information about five jobs waiting to be processed at stamping machine
| Job | Processing Time (hrs) | Due (hrs) |
Schedule the jobs based on the earliest due date
| Hours | |||||||||||||||
| Job |
Thus, calculate the average flow time that is required to finish the each job:
Now, calculating the average tardiness, it is given that job
The job
The job
The job
The job
Adding the delay time of the order and divide it by the number of the orders;
From the table, it is observed that job
Calculate the critical ratio by dividing the hours until due by the processing time for the each job.
| Job | Processing Time (hrs) | Due (hrs) | Critical ratio |
Now, schedule the based on the ascending order of the critical ratios.
| Hours | |||||||||||||||
| Job |
Calculate the average flow time by adding the delay time of the order and divide it by the number of the orders;
Calculate the tardiness for the each job,
that job
The job
The job
The job
The job
Adding the tardiness of the order and divide it by the number of the orders;
From the table, it is observed that the job
Schedule the jobs based on the
| Hours | |||||||||||||||
| Job |
Thus, calculate the average flow time that is required to finish the each job:
Now, calculating the average tardiness, it is given that job
The job
The job
The job
Now, calculate the average tardiness,
Thus, the job
From the above calculation, the average flow time based on methods:
Therefore, shortest processing time gives the lowest average flow time.
(b)
Interpretation:
The best sequence in terms of the average tardiness:
Concept Introduction:
Schedule the job on the basis of the
Schedule the job on the basis of the
(b)
Explanation of Solution
Given information:
The table below contains the information about five jobs waiting to be processed at stamping machine
| Job | Processing Time (hrs) | Due (hrs) |
From the above calculation, the average tardiness based on the different methods,
Therefore, shortest processing time gives the lowest average tardiness.
(c)
Interpretation:
The finish time of job
Concept Introduction:
Schedule the job on the basis of the
Schedule the job on the basis of the
(c)
Explanation of Solution
Given information:
The table below contains the information about five jobs waiting to be processed at stamping machine
| Job | Processing Time (hrs) | Due (hrs) |
From the above calculations, the completion of the job
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Chapter 14 Solutions
Practical Operations Management
- An insurance claims work area has five claims waiting for processing as follows: Job Processing Time Due Date (Di ) 1 18 31 2 14 25 3 12 23 4 19 24 5 10 37 Use the Excel Sequencing template to find the average flowtime, average and maximum tardiness, and average lateness for the following sequences: SPT sequence, EDD sequence, and the sequence 4-3-2-1-5. Round your answers for the average values to two decimal places. The SPT sequence is - - - - . Average Flow Time Average Tardiness Maximum Tardiness Average Lateness The EDD sequence is - - - - . Average Flow Time Average Tardiness Maximum Tardiness Average Lateness 4-3-2-1-5 sequence: Average Flow Time Average Tardiness Maximum Tardiness Average Lateness What sequencing rule do you recommend? The ___________ is recommended as it minimizes average flow time and number of jobs in system.arrow_forwardThe following jobs are waiting to be processed at Jeremy LaMontagne's machine center. Today is day 250. Using the critical ratio scheduling rule, in what sequence would the jobs be processed?arrow_forwardwhere the consulting company has five jobs in its backlog. Create a schedule usingthe EDD rule, calculating the average days past due and flow time. In this case, does EDD outperformthe FCFS rule?arrow_forward
- Consider the following process at a pharmacy.Customers drop off their prescriptions either in the drive-through counter or in the front counter of the pharmacy. Customers can request that their prescription be filled immediately. In this case, they have to wait between 15 minutes and one hour depending on the current workload. Most customers are not willing to wait that long, so they opt to nominate a pickup time at a later point during the day. Generally, customers drop their prescriptions in the morning before going to work (or at lunchtime) and they come back to pick up the drugs after work, typically between 5pm and 6pm. When dropping their prescription, a technician asks the customer for the pick-up time and puts the prescription in a box labelled with the hour preceding the pick-up time. For example, if the customer asks to have the prescription be ready at 5pm, the technician will drop it in the box with the label 4pm (there is one box for each hour of the day). Every hour, one…arrow_forwardConsider the following process at a pharmacy. Customers drop off their prescriptions either in the drive-through counter or in the front counter of the pharmacy. Customers can request that their prescription be filled immediately. In this case, they have to wait between 15 minutes and one hour depending on the current workload. Most customers are not willing to wait that long, so they opt to nominate a pickup time at a later point during the day. Generally, customers drop their prescriptions in the morning before going to work (or at lunchtime) and they come back to pick up the drugs after work, typically between 5pm and 6pm. When dropping their prescription, a technician asks the customer for the pick-up time and puts the prescription in a box labelled with the hour preceding the pick-up time. For example, if the customer asks to have the prescription be ready at 5pm, the technician will drop it in the box with the label 4pm (there is one box for each hour of the day). Every hour, one…arrow_forwardConsider the following process at a pharmacy. Customers drop off their prescriptions either in the drive-through counter or in the front counter of the pharmacy. Customers can request that their prescription be filled immediately. In this case, they have to wait between 15 minutes and one hour depending on the current workload. Most customers are not willing to wait that long, so they opt to nominate a pickup time at a later point during the day. Generally, customers drop their prescriptions in the morning before going to work (or at lunchtime) and they come back to pick up the drugs after work, typically between 5pm and 6pm. When dropping their prescription, a technician asks the customer for the pick-up time and puts the prescription in a box labelled with the hour preceding the pick-up time. For example, if the customer asks to have the prescription be ready at 5pm, the technician will drop it in the box with the label 4pm (there is one box for each hour of the day). Every hour, one…arrow_forward
- Given the data below, using the SPT heuristic sequencing rule, determine the completion date and tardiness for each job as well as the average completion time and average tardiness for all four jobs. Which of the following statements is true? Job Processing time (days) Due date (in days) A 10 10 B 5 8 C 15 25 D 8 15 a.Jobs B and D will have no tardiness b.The tardiness for Job A is 12 days c.The average tardiness is 19.75 d.The average completion time is 6.5arrow_forwardConsider the following process at a pharmacy. Customers drop off their prescriptions either in the drive-through counter or in the front counter of the pharmacy. Customers can request that their prescription be filled immediately. In this case, they must wait between 15 minutes and one hour depending on the current workload. Most customers are not willing to wait that long, so they opt to nominate a pick-up time at a later point during the day. Generally, customers drop their prescriptions in the morning before going to work (or at lunchtime) and they come back to pick up the drugs after work, typically between 5pm and 6pm. When dropping their prescription, a technician asks the customer for the pick-up time and puts the prescription in a box labelled with the hour preceding the pick-up time. For example, if the customer asks to have the prescription be ready at 5pm, the technician will drop it in the box with the label 4pm (there is one box for each hour of the day). Every hour, one…arrow_forwardConsider the following process at a pharmacy. Customers drop off their prescriptions either in the drive-through counter or in the front counter of the pharmacy. Customers can request that their prescription be filled immediately. In this case, they must wait between 15 minutes and one hour depending on the current workload. Most customers are not willing to wait that long, so they opt to nominate a pick-up time at a later point during the day. Generally, customers drop their prescriptions in the morning before going to work (or at lunchtime) and they come back to pick up the drugs after work, typically between 5pm and 6pm. When dropping their prescription, a technician asks the customer for the pick-up time and puts the prescription in a box labelled with the hour preceding the pick-up time. For example, if the customer asks to have the prescription be ready at 5pm, the technician will drop it in the box with the label 4pm (there is one box for each hour of the day). Every hour, one…arrow_forward
- Consider the following process at a pharmacy. Customers drop off their prescriptions either in the drive-through counter or in the front counter of the pharmacy. Customers can request that their prescription be filled immediately. In this case, they must wait between 15 minutes and one hour depending on the current workload. Most customers are not willing to wait that long, so they opt to nominate a pick-up time at a later point during the day. Generally, customers drop their prescriptions in the morning before going to work (or at lunchtime) and they come back to pick up the drugs after work, typically between 5pm and 6pm. When dropping their prescription, a technician asks the customer for the pick-up time and puts the prescription in a box labelled with the hour preceding the pick-up time. For example, if the customer asks to have the prescription be ready at 5pm, the technician will drop it in the box with the label 4pm (there is one box for each hour of the day). Every hour, one…arrow_forwardstate whether or not each situation would be considered “compensable time” (and why or why not). An employee of a fast food chain has to arrive at work 15 minutes early to change into the“mascot” costume and it typically takes another 15 minutes at the end of the shift to change outof the costume and properly store it. Due to the cost of the costume, employees are notallowed to take the costume home. The “mascots” typically work from 10am – 2pm, to coverthe lunch rush periods. How much time would be “compensable” for the mascots, assumingthe conditions/schedule listed above?2) George is a Radiology Technician at a local hospital and when on call, is required to be nofurther than 30 minutes away from the facility. Is the “on call” time, compensable?arrow_forwardThe first five columns of the following table contain information about a set of four jobs that just arrived (end of Hour 0 or beginning of Hour 1) at an engine lathe. They are the only ones now waiting to be processed. Several operations, including the one at the engine lathe, remain to be done on each job. Determine the schedule by using (a) the CR rule and (b) the S/RO rule. Compare these schedules to those generated by FCFS, SPT, and EDD. Job ProcessingTime at EngineLathe (hours) TimeRemainingUntil Due Date(days) Number ofOperationsRemaining Shop TimeRemaining(days) CR S/RO 1 2 3 4 2.3 10.5 6.2 15.6 15 10 20 8 10 2 12 5 6.1 7.8 14.5 10.2 2.46 1.28 1.38 0.78 0.89 1.10 0.46 -0.44arrow_forward
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