1. 9-1 ELC 347 project management Day 19

2. Agenda Integrative Project –Part 4 Due –Part 5 Due Nov 24 (page 342) –Any of the first five sections can be resubmitted for rescoring prior to finals week. The recorded score will the average of the original score and the score on the resubmitted section. Assignment 6 Partially Corrected Assignment 7 Posted Today will discuss Project Scheduling: Networks, Duration Estimation, and Critical Path

3. Schedule for rest of semester Nov 10 –Chap 9 –IP part 4 Due Nov 13 –Chap 10 Nov 17 –Chap 11 –Assignment 7 due Nov 20 –Group work Nov 24 –Quiz 3 –IP part 5 Due Dec 1 –Project s 5 & 6 Dec 4 –Group Work –Assignment 8 due Dec 8 –Chap 12 –IP Part 6 due Dec 11 –Chap 13 & 14 Dec 18 @ 10 AM –Quiz 4 –IP Project’s due 6-3© 2007 Prentice-Hall, Inc

4. 9-4 Project Scheduling: Networks, Duration Estimation, and Critical Path Chapter 9 © 2007 Pearson Education

5. 9-5

6. Writing a paper Writing a research paper –Identify Topic –Research Paper –Write First Draft –Edit and rewrite paper –Prepare Class presentation –Complete Final Draft –Complete presentation –Hand-in paper and present topic in class Can this process be completed differently if assigned as group work? 9-6

7. 9-7

8. 9-8 Project Scheduling Terms Successors Predecessors Network diagram Serial activities Concurrent activities E D C B A F Merge activities Burst activities Node Path Critical Path Float Resource limited Forward pass Backward pass ES LS EF LF

9. 9-9 Network Diagrams Show interdependence Facilitate communication Help schedule resources Identify critical activities Determine project completion Show start & finish dates

10. 9-10 AOA Vs. AON The same mini-project is shown with activities on arc… C E D B F E C D B F …and activities on node.

11. 9-11 Node Labels Early Start Activity Float Activity Descriptor Late Start ID Number Activity Duration Late Finish Early Finish Basic math ES + DUR = EF LS + DUR = LF ES+AF=LS

12. 9-12 CPM versus PERT PERT was developed by US Navy in the 1950s’ CPM was developed by Remington Rand and DuPont around the same time. Only difference is in durations estimating –Pert uses 3 cases Most optimistic, most pessimistic and most likely and determines probability for each D o P o + D p O p +D e P e = final duration –CPM use only the most likely duration

13. 9-13 Duration Estimating Duration – the elapsed time from the start of an activity until it is finished Effort -- the actual time spent on the project Example –Tony work on a project task for 20 hours at 4 hours per day starting Monday mourning. The project task was completed Late Friday Effort – 20 hours Duration – 5 days

14. 9-14 Techniques for Estimating Duration Experience Historical data Research Modeling Experiments Breakdown/roll-up Delphi Method –Panel of experts Consultants Three outside Estimates Ranging Other techniques

15. 9-15

16. 9-16 Duration Estimation Methods Past experience Expert opinion Mathematical derivation – Beta distribution –Most likely (m) –Most pessimistic (b) –Most optimistic (a)

17. 9-17 TaskPredecessoramb Z--7815 YZ131619 XZ141822 WY, X121416 VW1413 TW61014 ST, V111419 1.Sketch the network described in the table. 2.Determine the expected duration and variance of each activity. Duration estimate.xls

18. 9-18 Constructing the Critical Path Forward pass – an additive move through the network from start to finish –Determines ES and EF using ES+DUR = EF –If 2 (or more) EF from proceeding uses largest Backward pass – a subtractive move through the network from finish to start –Determines LS and LF using LF- DUR = LS –If 2 (or more) LS from succeeding use smallest –Determine AF using LS-ES = AF Critical path – the longest path from end to end which determines the shortest project length

19. 9-19 Rules for Forward/Backward Pass Forward Pass Rules (ES & EF) –ES + Duration = EF –EF of predecessor = ES of successor –Largest preceding EF at a merge point becomes EF for successor Backward Pass Rules (LS & LF) –LF – Duration = LS –LS of successor = LF of predecessor –Smallest succeeding LS at a burst point becomes LF for predecessor

20. 9-20 Calculating a Project Duration Determine each activity and its predecessors Determine an estimated duration for each activity Find the “Critical Path” –Add up the durations along the critical path

21. 9-21 Whats the “Critical Path” The longest path based on precedence of activities and durations through a PERT/CPM network It’s critical because –Its combined length determines the length of the project –It has NO slack –Delay of any activities on the critical path delays the entire project

22. 9-22 Finding the critical path Use “forward pass” Calculations Each activity should have –ES  earliest possible Start time –EF  earliest possible finish time –DUR  duration –EF = ES + DUR ESDUREF Activity

23. 9-23 Example 347 A 7512 B

24. 9-24 Special Case If an activity has more than one processor its EPS is set to the latest EPF of all its processors 347 A 7512 C 055 B

25. 9-25 An example of forward pass 000 Start 841212 F 044 D 481212 C 2525 42929 Finish 055 A 1616 52121 I 2121 42525 J 448 E 1616 72323 H 1212 416 G 549 B

26. 9-26 Backwards Pass Use to calculate Slack –LS -> Latest start time –LF -> Latest finish time –TS -> total slack ESDUREF Activity LSTSLF

27. 9-27 An example of backward pass 000 Start 000 841212 F 1212 41616 044 D 004 481212 C 401212 2525 42929 Finish 2525 02929 055 A 338 1616 52121 I 1616 02121 2121 42525 J 2121 02525 448 E 841212 1616 72323 H 1818 22525 1212 416 G 1201616 549 B 831212

28. 9-28 TaskPredecessorTime A--4 BA9 CA11 DB5 EB3 FC7 GD, F3 HE, G2 KH1 1.Sketch the network described in the table. 2.Determine the ES, LS, EF, LF, and slack of each activity SLACK.xls cp.mpp

29. 9-29 Examine Critical Path for Reality Check Is the total duration typical? Are the durations of the CP activities typical? Reexamine all CP activity durations Reexamine assumptions

30. 9-30 Laddering Activities Project ABC can be completed more efficiently if subtasks are used A(3)B(6)C(9) ABC=18 days Laddered ABC=12 days A 1 (1)A 2 (1)A 3 (1) B 1 (2)B 2 (2)B 3 (2) C 1 (3)C 2 (3)C 3 (3)

31. 9-31 Hammock Activities Used as summaries for subsets of activities 0 A5 0 55 5 B15 5 1015 15 C18 15 318 0 Hammock18 01818 Useful with a complex project or one that has a shared budget

32. 9-32 Reducing the Critical Path Eliminate tasks on the CP Convert serial paths to parallel when possible Overlap sequential tasks Shorten the duration on critical path tasks Shorten –early tasks –longest tasks –easiest tasks –tasks that cost the least to speed up