JOB SHOP SCHEDULING

1. JOB SHOP SCHEDULING Prepared by Res.Asst.Hanife Demiralp

2. One Machine Scheduling EXAMPLE: Suppose that 6 employees are to be trained to operate different machines by a single trainer who can train only one person at a time. The time to train each person varies and is given in the table along with due dates and the number of operations involved.

5. Solution Screen Lateness is the difference between flow time and due date Flow time is the time that each job ends

6. The solution of one-machine scheduling: the sequence according to Shortest Processing Time (SPT) is Employee 1, Employee 3, Employee 2, Employee 4 and Employee 5. Because employee 1 has the shortest processing time, then employee 3 has the second shortest processing time etc.

7. Gantt Chart of Scheduling

8. Example 2: First Come First Served

9. Date received must be less than or equal to starting date.

10. Solution Screen Completion time = Flow Time + Starting Day - 1 Flow time of job5= 100-82+9=27 Flow Time of job2= 100-87+5+9=27 etc.

11. The result according to FCFS (First Come First Server); the sequence (schedule) is job 5 is first, then job 2, job 4, job 6, job 1 and last one is job 3. Because the FCFS option selected, the program will schedule the jobs according to the receipt day.

12. Example 3: Schedule According to Slack Slack is defined as the due date – time required to process a job. In order to use slack, the due date must be given.

13. Data Table

14. Solution Screen The jobs are scheduled according to increasing order of slack!

15. Gantt Chart of Schedule