Asked by Nicki Gagliano on Apr 26, 2024
Verified
A firm that specializes in desktop publishing for local charities has agreed to take on the following jobs. The firm has not decided which dispatching rule to apply in order to prioritize the jobs and fix them into the schedule. All dates are specified as days from Day 1.
Start day 1 Data Received Time Due Date A 11632 B 12127 C 11114D1860 E 11411 F 1932\begin{array} { | r | r | r | r | } \hline \text { Start day } & 1 & & \\\hline \text { Data } & & & \\\hline & \text { Received } & \text { Time } & \text { Due Date } \\\hline \text { A } & 1 & 16 & 32 \\\hline \text { B } & 1 & 21 & 27 \\\hline \text { C } & 1 & 11 & 14 \\\hline \mathrm { D } & 1 & 8 & 60 \\\hline \text { E } & 1 & 14 & 11 \\\hline \text { F } & 1 & 9 & 32 \\\hline\end{array} Start day Data A B C D E F 1 Received 111111 Time 1621118149 Due Date 322714601132 a. Complete the following table. Show your supporting calculations below.
b. Which dispatching rule has the best score for flow time?
c. Which dispatching rule has the best score for work-in-process (jobs in the system)?
d. Which dispatching rule has the best score for lateness?
Dispatching Average Average Number Number of Average Rule Flow Time of Jobs Jobs Late Lateness FCFS SPTLPT EDD SLACKCR\begin{array}{|l|l|l|l|l|}\hline\text { Dispatching } & \text { Average } & \text { Average Number } & \text { Number of } & \text { Average } \\\text { Rule } & \text { Flow Time } & \text { of Jobs } & \text { Jobs Late } & \text { Lateness }\\\hline \text { FCFS } & & & & \\\hline\operatorname{SPT} & \\\hline \mathrm{LPT} & \\\hline \text { EDD } & \\\hline \operatorname{SLACK} & \\\hline \mathrm{CR} & \\\hline\end{array} Dispatching Rule FCFS SPTLPT EDD SLACKCR Average Flow Time Average Number of Jobs Number of Jobs Late Average Lateness
Dispatching Rule
A guideline or algorithm used in scheduling to determine the sequence in which work orders should be processed in a manufacturing or service system.
Flow Time
The total time a product or a piece of work requires to move through a production process, from start to finish.
Work-In-Process
Inventory that includes materials that have been released for production but are not yet complete, representing a critical stage in manufacturing and costing processes.
- Comprehend fundamental dispatching regulations and their utilization in planning schedules.
- Analyze how different scheduling strategies perform by measuring average flow time, work-in-process, lateness, and makespan.
- Determine the best scheduling technique in accordance with certain performance standards.
Verified Answer
AC
Alonzo ClaybrookApr 27, 2024
Final Answer :
a)
Method Average Flow Time Average number of jobs insystem Utilization Number of late jobs AverageLate Time FCFS 513.8734180.25817425 SPT 38.666672.9367090.340517420.5 LPT 53.54.0632910.246106525.16667 Due Date 49.53.7594940.265993620.16667 Slack 49.53.7594940.265993620.16667 Crit Ratio 49.53.7594940.265993620.16667\begin{array}{rrrrrr}\text { Method }&\begin{array} { l } \text {Average }\\ \text {Flow Time }\\\end{array}&\begin{array} { l } \text { Average}\\ \text { number of}\\ \text { jobs in}\\ \text {system }\\\end{array}&\text { Utilization }&\begin{array} { l } \text {Number of }\\ \text { late jobs}\\\end{array}&\begin{array} { l } \text { Average}\\ \text {Late Time }\\\end{array}\\\text { FCFS } & 51 & 3.873418 & 0.25817 & 4 & 25 \\\text { SPT } & 38.66667 & 2.936709 & 0.340517 & 4 & 20.5 \\\text { LPT } & 53.5 & 4.063291 & 0.246106 & 5 & 25.16667 \\\text { Due Date } & 49.5 & 3.759494 & 0.265993 & 6 & 20.16667 \\\text { Slack } & 49.5 & 3.759494 & 0.265993 & 6 & 20.16667 \\\text { Crit Ratio } & 49.5 & 3.759494 & 0.265993 & 6 & 20.16667\end{array} Method FCFS SPT LPT Due Date Slack Crit Ratio Average Flow Time 5138.6666753.549.549.549.5 Average number of jobs insystem 3.8734182.9367094.0632913.7594943.7594943.759494 Utilization 0.258170.3405170.2461060.2659930.2659930.265993Number of late jobs445666 AverageLate Time 2520.525.1666720.1666720.1666720.16667 b) SPT
c) SPT
d) EDD, Slack and CR are tied
Method Average Flow Time Average number of jobs insystem Utilization Number of late jobs AverageLate Time FCFS 513.8734180.25817425 SPT 38.666672.9367090.340517420.5 LPT 53.54.0632910.246106525.16667 Due Date 49.53.7594940.265993620.16667 Slack 49.53.7594940.265993620.16667 Crit Ratio 49.53.7594940.265993620.16667\begin{array}{rrrrrr}\text { Method }&\begin{array} { l } \text {Average }\\ \text {Flow Time }\\\end{array}&\begin{array} { l } \text { Average}\\ \text { number of}\\ \text { jobs in}\\ \text {system }\\\end{array}&\text { Utilization }&\begin{array} { l } \text {Number of }\\ \text { late jobs}\\\end{array}&\begin{array} { l } \text { Average}\\ \text {Late Time }\\\end{array}\\\text { FCFS } & 51 & 3.873418 & 0.25817 & 4 & 25 \\\text { SPT } & 38.66667 & 2.936709 & 0.340517 & 4 & 20.5 \\\text { LPT } & 53.5 & 4.063291 & 0.246106 & 5 & 25.16667 \\\text { Due Date } & 49.5 & 3.759494 & 0.265993 & 6 & 20.16667 \\\text { Slack } & 49.5 & 3.759494 & 0.265993 & 6 & 20.16667 \\\text { Crit Ratio } & 49.5 & 3.759494 & 0.265993 & 6 & 20.16667\end{array} Method FCFS SPT LPT Due Date Slack Crit Ratio Average Flow Time 5138.6666753.549.549.549.5 Average number of jobs insystem 3.8734182.9367094.0632913.7594943.7594943.759494 Utilization 0.258170.3405170.2461060.2659930.2659930.265993Number of late jobs445666 AverageLate Time 2520.525.1666720.1666720.1666720.16667 b) SPT
c) SPT
d) EDD, Slack and CR are tied
Learning Objectives
- Comprehend fundamental dispatching regulations and their utilization in planning schedules.
- Analyze how different scheduling strategies perform by measuring average flow time, work-in-process, lateness, and makespan.
- Determine the best scheduling technique in accordance with certain performance standards.