1. Projmgmt-1/14 DePaul University Project Management I - Realistic Scheduling Instructor: David A. Lash

2. Projmgmt-2/14

3. Projmgmt-3/14 Sequencing Tasks Either Task 1 or 2 can go first (Can be concurrent) Task 5 can't start until 2 Task 3 needs 1 & 2 Task 4 needs 3 (therefore needs 1 & 2 too!)

4. Projmgmt-4/14 Correct Network Diagram How get from network diagram to schedule?

5. Projmgmt-5/14 Step 4 - Calculate Initial Schedule u PERT Charts - Program, Evaluation & Review Technique - Calculate 4 variables: – Early Start (ES) - The earliest date a task can BEGIN – Early Finish (EF) - The earliest date a task can END – Late Start (LS) - The latest date a task can BEGIN – Late Finish (LF) - The latest date a task can END Early Start Early Finish Late Finish Late StartFloat Days

6. Projmgmt-6/14 Step 4 - Diagram ES,EF, LS, LF, FL Early Start Early Finish Late Finish Late StartFloat Days

7. Projmgmt-7/14 Step 4 - Calculate Initial Schedule u There are 3 major steps – Step 1 - Forward Pass - Determine the Early Start (ES) and Early Finish (EF) for each task u Works through tasks from start to finish – Step 2 - Backward Pass - Determine the late start (LS) and late finish (LF) dates. u Works backward through tasks from end to start – Step 3 - Calculate Float - Determine the schedule flexibility for each task. u Calculated by subtracting the ES from LS.

8. Projmgmt-8/14 Step 4 - Calculate Initial Schedule u Step 1 - Forward Pass - Work forward from the start to calculate ES and EF u Task 1 & 2 is assumed to be the first day of the project.

9. Projmgmt-9/14 Step 4 - Calculate Initial Schedule u Step 1 - Forward Pass - Calculate ES and EF u Task 5 finishes after task 2.

10. Projmgmt-10/14 Step 4 - Calculate Initial Schedule u Step 1 - Forward Pass - Calculate ES and EF u Task 3 finishes after task 1 & 2. (4 after 3)

11. Projmgmt-11/14 Step 4 - Calculate Initial Schedule Start Finish

12. Projmgmt-12/14 Step 4 - Calculate Initial Schedule u There are 3 major steps – Step 1 - Forward Pass - Determine the Early Start (ES) and Early Finish (EF) for each task u Works through tasks from start to finish – Step 2 - Backward Pass - Determine the late start (LS) and late finish (LF) dates. u Works backward through tasks from end to start – Step 3 - Calculate Float - Determine the schedule flexibility for each task. u Calculated by subtracting the ES from LS.

13. Projmgmt-13/14 Step 4 - Calculate Initial Schedule u Backward Pass - – Set Project Finish Date - u Calculate the LS and LF dates – Determine The Last Start for the last CP task (5) u Last finish is the minimal time = 16 u The finish day = 16 therefore LS = 5 (16+1-12) = 5 u if task 5 not start by day 5 the project will be late Finish LS LF Finish day is finish day of project (17)

14. Projmgmt-14/14 Step 4 - Calculate Initial Schedule u Backward Pass - – Take the next CP date (task 2). Find LS u The finish day = 4 therefore LS is 1 (4+1- 4). u If task 2 not start by day 1 the project will be late! Finish LS LF Finish day is start date of next task.

15. Projmgmt-15/14 Step 4 - Calculate Initial Schedule u Backward Pass - (Repeat for non - CP items) – Start with last non-CP task (task42). u Find LF - For task 4 with dur=1 LF=16 u Find LS = 12 (15+1-1). u If task 4 not started on day 16 will be late! u If task 3 not start on day 12 will be late! Finish LS LF Finish day is start date of next task. LF = 15 latest it can finish LS = 15+1 -5 = 11 - latest it can start

16. Projmgmt-16/14 Step 4 - Calculate Initial Schedule Start Finish

17. Projmgmt-17/14 Step 4 - Calculate Initial Schedule u There are 3 major steps – Step 1 - Forward Pass - Determine the Early Start (ES) and Early Finish (EF) for each task u Works through tasks from start to finish – Step 2 - Backward Pass - Determine the late start (LS) and late finish (LF) dates. u Works backward through tasks from end to start – Step 3 - Calculate Float - Determine the schedule flexibility for each task. u Calculated by subtracting the ES from LS.

18. Projmgmt-18/14 Step 3 - Calculate Float u Float? - Some tasks have schedule flexibility – others have none - E.g, those in the Critical Path – it is a measure of schedule flexibility of a task u Float = ES - LS - duration

19. Projmgmt-19/14 Step 4 - Calculate Initial Schedule Start Finish FL=(16+1)-5-12 FL=(4+1)-1-4 FL=(16+1)-9-1 FL=(11+1)-1-2FL=(15+1)-5-4

20. Projmgmt-20/14 Time-Scaled View u Figure 7-5 page 136 shows a time scaled view of above diagram – wider boxes show the task duration – float is shown indirectly u Figure 7.6 shows network diagram for entire home landscape project

21. Projmgmt-21/14

22. Projmgmt-22/14 Step 5: Assign & Level Resources u Goal: Optimize the use of resources – continuos use of fewest resources possible – avoid repeatedly adding a reusing resources – that is, limited people and resources affect the schedule u Figure 7.6 network diagram shows can build fence and put in lawn at the same time. – Not take into consideration over allocation of teens – Figure 7.11 shows the resource shreadsheet. u Note teens heavily overallocated – Figure 7.13 shows same project with resources leveled (3 teens @ 8 hrs per day with no more than 24 total hours per day).

23. Projmgmt-23/14 Step 5: Assign & Level Resources: The Process u Resources: People, equipment, and raw materials – Resource leveling - focus only on people and equipment u 4 steps to level resources 1. Forecast resources throughout project. u Use resource spreadsheet such as figure 7.11 u Creates an early start schedule - usually with lots of uneconomical resource peaks and valleys (e.g., teen overallocation) 2. Identify resource peaks u Use resource spreadsheet (figure 7.11) & resource histogram (figure 7.12)

24. Projmgmt-24/14 Step 5: Assign & Level Resources: The Process (steps 3 & 4) u 4 steps to level resources 1. Forecast resources throughout project. 2. Identify resource peaks 3. Delay non-critical tasks within their float. u Use the float to fill in the resource valleys (I.e., spreading resources out over time when schedule permits) u See figure 7.13 compare to figure 7.12- task 5 was delayed within float to balance resources. 4. Re-examine resource peaks - u Look again at peaks, can redistribute schedule affecting resource? u Task 12 on 7.13 changed from 2 teens for 1 day to 1 teen for 3 days

25. Projmgmt-25/14 Step 5: Assign & Level Resources: Now what? u What happens if new schedule still unexceptable? – The project date might now be pushed out longer than acceptable u You could accept the new date u Work additional resources u likely need to involve sponsor &/or customer to make decision(s)