Example of repetitive project with probabilistic activity durations and work breaks
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The document analyzes the effects of scheduling work breaks in repetitive projects to reduce project duration and idle time. It presents various project schedules with differing numbers of work breaks, showing significant improvements in project duration and a reduction in idle time. Notably, the schedule with three work breaks achieves an average project duration of 342 days, compared to 449 days without breaks.
Example of repetitive project with probabilistic activity durations and work breaks
- 1. (IV) Work Breaks 1 Schedule work breaks in repetitive projects in order to reduce project duration Presented by Chachrist Srisuwanrat 2008 EXAMPLE OF SCHEDULING A REPETITIVE PROJECT WITH PROBABILISTIC ACTIVITY DURATIONS AND WORK BREAKS
- 2. (IV) Work Breaks 2 Example of a Repetitive Project with Work Breaks A B C E D F G H J SQS1 SQS2 SQS3 SQS4 SQS5
- 3. (IV) Work Breaks 3 0 1 2 3 4 5 6 7 8 9 10 0 30 60 90 120 150 180 210 240 270 300 330 360 390 420 450 Time Unit A B C D E F G H J Average Total Idle Time = 1 day Average Project Duration = 449 days Controlling Sequence 0 1 2 3 4 5 6 7 8 9 10 0 30 60 90 120 150 180 210 240 270 300 330 360 390 420 450 Time Unit A B C D E F G H J Average Total Idle Time = 438 days Average Project Duration = 277 days Early-start schedule has project duration of 277 days but also has 438 days of idle time. SQS-AL with no work breaks has average project duration of 449 days. SQS-AL schedule with no work breaks. --288J --102H --282G --78F --120E --120D --68C --114B --0A Crew Return Date (CLT2) Work Break Location Crew Arrival Date (CLT1) Activity
- 4. (IV) Work Breaks 4 0 1 2 3 4 5 6 7 8 9 10 0 30 60 90 120 150 180 210 240 270 300 330 360 390 420 450 Time Unit A B C D E F G H J Average Total Idle Time = 3 days Average Project Duration = 376 days Controlling Sequence 0 1 2 3 4 5 6 7 8 9 10 0 30 60 90 120 150 180 210 240 270 300 330 360 390 420 450 Time Unit A B C D E F G H J Average Total Idle Time = 3 days Average Project Duration = 342 days Controlling Sequence SQS-AL schedule with two work breaks has average project duration of 376 days. SQS-AL schedule with three work breaks has average project duration of 342 days. SQS-AL schedule with two work breaks. SQS-AL schedule with three work breaks. --180J --84H 254G7-G8174G --60F --102E --44D 98C4-C522C 134B5-B638B --0A Crew Return Date (CLT2) Work Break Location Crew Arrival Date (CLT1) Activity --214J --102H 288G7-G8208G --78F --102E --78D --68C 134B5-B638B --0A Crew Return Date (CLT2) Work Break Location Crew Arrival Date (CLT1) Activity B5-B6 G7-G8 C4-C5 Improve duration by 73 days Improve duration by 107 days
- 5. (IV) Work Breaks 5 Method Work Break Positions Average Project Duration Average Total Idle Time Project Duration plus idle time CPM - 277 438 715 SQS-AL - 449 1 450 SQS-AL* G7-G8 410 3 413 SQS-AL** G7-G8, B5-B6 376 3 379 SQS-AL*** G7-G8, B5-B6,C4-C5 342 3 345 Results from Introducing Work Breaks • SQS-AL reduces idle time by 22 months, compared to CPM. • SQS-AL*** with 3 work breaks reduces project duration by 5 months, compared to SQS-AL w/o work breaks.