[經(jīng)濟(jì)學(xué)]scheduling調(diào)度與規(guī)劃(編輯修改稿)
2024-11-15 02:21 本頁(yè)面
【文章內(nèi)容簡(jiǎn)介】 yright 2021 John Wiley amp。 Sons, Inc. 1619 A(10)/5 = B(15)/10 = C (5)/2 = D(12)/8 = E (8)/6 = Simple Sequencing Rules: CR E 0 6 6 8 0 D 6 8 14 12 2 B 14 10 24 15 9 A 24 5 29 10 19 C 29 2 31 5 26 CR START PROCESSING COMPLETION DUE SEQUENCE TIME TIME TIME DATE TARDINESS Copyright 2021 John Wiley amp。 Sons, Inc. 1620 Simple Sequencing Rules: SPT C 0 2 2 5 0 A 2 5 7 10 0 E 7 6 13 8 5 D 13 8 21 12 9 B 21 10 31 15 16 SPT START PROCESSING COMPLETION DUE SEQUENCE TIME TIME TIME DATE TARDINESS Copyright 2021 John Wiley amp。 Sons, Inc. 1621 Simple Sequencing Rules: Summary FCFS 3 23 DDATE 3 16 SLACK 4 16 CR 4 26 SPT 3 16 AVERAGE AVERAGE NO. OF MAXIMUM RULE COMPLETION TIME TARDINESS JOBS TARDY TARDINESS Copyright 2021 John Wiley amp。 Sons, Inc. 1622 Sequencing Jobs Through Two Serial Process Johnson’s Rule 1. List time required to process each job at each machine. Set up a onedimensional matrix to represent desired sequence with of slots equal to of jobs. 2. Select smallest processing time at either machine. If that time is on machine 1, put the job as near to beginning of sequence as possible. 3. If smallest time occurs on machine 2, put the job as near to the end of the sequence as possible. 4. Remove job from list. 5. Repeat steps 24 until all slots in matrix are filled and all jobs are sequenced. Copyright 2021 John Wiley amp。 Sons, Inc. 1623 Johnson’s Rule JOB PROCESS 1 PROCESS 2 A 6 8 B 11 6 C 7 3 D 9 7 E 5 10 C E A B D Copyright 2021 John Wiley amp。 Sons, Inc. 1624 Johnson’s Rule (cont.) A B C D E E A D B C Process 1 (sanding) 5 11 20 31 38 E A D B C Process 2 (painting) 5 15 23 30 37 41 Idle time Completion time = 41 Idle time = 5+1+1+3=10 Copyright 2021 John Wiley amp。 Sons, Inc. 1625 Guidelines for Selecting a Sequencing Rule 1. SPT most useful when shop is highly congested 2. Use SLACK for periods of normal activity 3. Use DDATE when only small tardiness values can be tolerated 4. Use LPT if subcontracting is anticipated 5. Use FCFS when operating at lowcapacity levels 6. Do not use SPT to sequence jobs that have to be assembled with other jobs at a later date Copyright 2021 John Wiley amp。 Sons, Inc. 1626 Monitoring ? Work package ? Shop paperwork that travels with a job ? Gantt Chart ? Shows both planned and pleted activities against a time scale ? Input/Output Control ? Monitors the input and output from each work center Copyright 2021 John Wiley amp。 Sons, Inc. 1627 1 2 3 4 5 6 8 9 10 11 12 Days 1 2 3 Today’s Date Job 32B Job 23C Job 11C Job 12A Facility Key: Planned activity Completed activity Behind schedule Ahead of schedule On schedule Gantt Chart Copyright 2021 John Wiley amp。 Sons, Inc. 1628 Input/Output Control Input/Output Report
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