1. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 1 CHAPTER 7 DETAILED PLANNING - Schedule Estimating and Negotiating NOTICE: This material is copyrighted and may be copied or downloaded ONCE ONLY by students who are registered in this course at Southern Methodist University or National Technological University.

2. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 2 Detailed Planning Process Estimate Size Estimate Effort and Cost Estimate Schedule Evaluate Source Information Statement of Work Requirements Constraints Standards Processes History etc. WBSSize Effort & Cost Schedule OK Complete Detailed Planning Revise & Negotiate Not OK

3. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 3 Three Levels of Schedule Detail Top Level Schedule – Generally produced during initial planning, based on program master schedule, constraints, deadlines, etc. Generic Schedule – Generally produced during effort estimation, based on the process and the information gained from estimating models

4. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 4 Three Levels of Schedule Detail (continued) Detailed Schedule – Generally produced when you are about to execute the project or a phase of the project

5. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 5 Here We Will Cover Two Topics How to verify that the top level and generic schedule are realistic – Normally this is done as part of the effort estimating process How to develop a detailed schedule – This tends to be done when you are just about to begin a particular phase of development – But it can be done at a higher level for other purposes

6. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 6 Verifying that the Schedule is Reasonable Two issues are of concern: Total Time to Do the Job Percent of Time and Effort in Each Phase of the Job How do you know whether the top level schedule is realistic? How do you determine schedule details?

7. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 7 Total Time Needed Total time needed to do the project is a direct factor of – Size and nature of software developed – Organizational capability – Process and methods – Time constraints – Financial constraints This can vary significantly from one organization to the next

8. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 8 Estimating the Time Needed Estimation models like Cocomo can be used to predict the length of the schedule These models predict an ideal or optimal schedule

9. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 9 Estimating the Time Needed (continued) You can vary the actual schedule to fit your conditions – You have flexibility in matching the schedule to other project constraints – But you can drive up cost as you deviate from the optimal

10. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 10 The Optimal Schedule...... depends on people, process, nature of task, environment, etc. … Different models make different assumptions about these factors, reflecting the experience of those who developed the models Until we have a better theoretical foundation, experience remains the best way of predicting your optimal schedule

11. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 11 Total Time to Do the Job Cocomo Formula... e =.38 for organic.35 for semi-detached.32 for embedded Effort is measured in staff months, as computed by the Cocomo formula (basic, intermediate, or detailed) Schedule is measured in calendar months Schedule = 2.5 * Effort e

12. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 12 Notes on Cocomo Formula This formula assumes schedule compression adjustment factor = 1 (nominal) In other words, the schedule computed by Cocomo is an ideal schedule. – Yours is probably different. Schedule = 2.5 * Effort e

13. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 13 The Cocomo Model of Time vs Effort staff- days required to do the work Calendar Time Allocated for the Work Optimal Schedule

14. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 14 Beware of Circular Relationship Schedule length is a function of effort in most models, including Cocomo If your schedule is different from the Cocomo ideal, then you must: – Change the “schedule compression” cost adjustment factor – Recompute the effort (it should go up) – Do NOT recompute schedule as a function of effort, because it is no longer valid

15. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 15 Other Models Give Different Formulas for Time SLIM formula for TOTAL effort (lifetime): SLIM equation for development effort vs development time is slightly different: Size = C k * Effort 1/3 * t 4/3 So t 4/3 = Size / C k * Effort 1/3 ) So t = (Size / C k * Effort 1/3 )) 3/4 DE = Constant / Time 4

16. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 16 0 2 4 6 8 10 12 14 16 18 0.50.60.70.80.911.11.2 RELATIVE TIME RELATIVE EFFORT EFFORT = CONSTANT / TIME4 Putnam’s “SLIM” Time vs. Size Equation

17. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 17 Why Do Models Vary on Schedule? Grady and Caswell compare five different sources (p34, 35) (see references) Differences stem from: – Type of software being developed – Schedule compression – Organizational differences – Process and methods

18. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 18 What to Do about Variation Hewlett-Packard recommendations: – Measure actual data & keep for the future – Count everything (overtime, etc.) Once you know YOUR organizational behavior, you can better calibrate the models to fit your experience

19. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 19 For Small Projects... General formulas tend to fit large projects better than small ones And you may not have a good data base of historical schedule information... So it may be better to estimate the time in a more detailed manner, as will be shown in the next section

20. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 20 Time may require Adjustment Actual project may require a different amount of time than the “ideal” computed by the models Project constraints may also affect the schedule You have a lot more flexibility with schedule than you do with size or cost

21. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 21 When Will Each Specific Task be Performed? This requires developing a more detailed schedule Which can also be used to give a more accurate estimate of the total time

22. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 22 When Will Each Specific Task be Performed? (continued) Generally you start with the top level schedule from initial planning, or the generic schedule developed during the effort estimate, and develop a more detailed schedule Very finely detailed schedules are best done just prior to performing the actual work

23. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 23 Developing the Detailed Schedule I Need a Detailed Schedule! Tell me How Long it will Take and When Each Task will be Complete. What do I do now? Yes, Sir! Right Away, Sir.

24. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 24 What are the Details of the Schedule?

25. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 25 Techniques for Developing & Documenting a Detailed Schedule PERT Charts (PDM) – Show dependencies – Can expand to show resources, timing, and critical path GANTT Charts – Show timing and parallelism Network Charts – Combine the benefits of PERT and GANTT – But you need a tool to manage them

26. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 26 Steps of Detailed Scheduling 1) Task Dependency and Flow – Shows dependencies, but not timing 2) Task Duration – Shows minimum schedule length – Identifies the critical path 3) Critical Path Analysis – Determines what must change if the schedule is to be reduced

27. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 27 Steps of Detailed Scheduling 4) Resource Requirements – Shows manpower loading, cash flow, etc. 5) GANTT Chart – Shows relative timing – But not the dependencies 6) Network Chart – Combines GANTT and PERT

28. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 28 PERT Charts & Critical Path Analysis

29. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 29 PERT “PERT” stands for “Program Evaluation and Review Technique” or “Performance Estimating & Reporting Tool” (depending on which author you read)

30. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 30 PERT Origins PERT was developed in the 1940’s as a management tool for complex projects In its fullest form, PERT involves complex statistical analysis of project schedules and plans

31. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 31 PERT Charts The basic tool of the PERT technique is the PERT Chart, which represents the schedule and resource needs of a project The PERT chart uses the Precedence Diagramming Method (PDM), which is similar to a flow chart, to represent the dependencies among activities

32. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 32 A Minimal PERT Chart... Lists activities to be performed (from WBS) Indicates dependencies – Activity X must precede activity Y, etc. – This information comes in part from initial planning (life cycle analysis, process definition)

33. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 33 Sample PERT Chart from Organizational Planning (in Early Planning Steps) PrototypeFinal DesignBuildDesign Keyboard CodeDesign Keyboard Software Test Build Keyboard Emulation Delivery Subcontracted SW for Numeric Key Pad Contract This can be produced by hand or with a project management or scheduling tool.

34. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 34 PrototypeFinal DesignBuildDesign Keyboard CodeDesign Keyboard Software Test Build Keyboard Emulation Delivery Subcontracted SW for Numeric Key Pad Contract An Alternative PERT Notation Touching boxes implies dependency Used to reduce space Used later in this course

35. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 35 List each task on a “post-it note” or index card Lay out the tasks on a board Indicate task dependencies with lines (arcs) Developing a PERT Chart Step 1 - Task Dependencies Task 1 Task 3 Task 6Task 7 Task 8 Task 2Task 5 Task 4 Task 9

36. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 36 Design Test Code Design Spec Integrate Develop Hardware Code VerifyTest Evaluating Dependencies

37. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 37 “Test” Task depends on “Code” and “Test Code” Design Test Code Design Spec Integrate Develop Hardware Code VerifyTest Identifying Dependencies What depends on what?

38. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 38 Identifying Dependencies What dependencies are unknown? Design Test Code Design Spec Integrate Develop Hardware Code VerifyTest Who needs this? (no successor)

39. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 39 Identifying Dependencies What depends on what? Design Test Code Design Spec Integrate Develop Hardware Code VerifyTest External task that we depend on

40. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 40 Finish to Start First task must finish before the second starts Start to Start Second task must start x months after first starts Finish to Finish Second task must finish y months after first finishes Types of PERT Dependencies x y Task 5 Task 2 3 7 6 Task 1Task 3Task 6Task 7 Task 8 Task 4 Task 9

41. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 41 With most PERT tools, you can specify a priority among parallel tasks Task 1 Task 3 Task 5 Task 2 Task 4 Task 5 Task 1 Task 3 Task 2 Task 4 Verifying Dependencies Do not overconstrain -- use only the the essential dependencies The following PERT chart represents a much more flexible plan

42. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 42 What to Learn from a Task Dependency PERT Chart Identify dependencies you did not know existed Identify missing dependencies where you do not know the successor or the predecessor Identify critical dependencies, such as a hardware activity that will hold you up if it is late

43. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 43 NOTE PERT Charts are a good method for developing a detailed process description as well as developing a project schedule PrototypeFinal DesignBuildDesign Keyboard CodeDesign Keyboard Software Test Build Keyboard Emulation Delivery Subcontracted SW for Numeric Key Pad Contract

44. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 44 Developing a PERT Chart Step 2 - Task Duration Lay out a Time Line at the bottom of the board For each task, estimate its duration and write that information on the post-it note. – Can be minimum feasible duration or expected duration based on availability of resources Place each task in its appropriate position relative to the time line

45. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 45 Developing a PERT Chart Step 2 - Task Duration (continued) Proper placement shows earliest start and end date for each task 20 weeks 8 weeks Minimum total time for whole activity is 26 weeks JFMAMJJASOND 6 weeks 8 weeks 12 weeks 26 weeks

46. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 46 What to Learn After Durations are Added The first task to focus on is the very last task – Will it complete by the project deadline? If not, how can you make the whole schedule shorter? The answer starts with determining the Critical Path

47. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 47 The Critical Path is... … the longest calendar path through the schedule from the first to the last activity Task A Task C Task B Task D Task E The Critical Path in the above example is A,C,D

48. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 48 The Critical Path is... … the path that must be shortened in order to shorten the whole schedule … the path that drives schedule slips – If a critical path task slips, the whole schedule slips … the riskiest part of the schedule Be especially wary when the critical path involves dependency on external tasks that you do not control!

49. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 49 If the schedule is small, “eyeball” and determine which path is the longest. Otherwise a tool can be used Critical Path => min possible schedule Critical Path Tasks Non-Critical Path Tasks Developing a PERT Chart Step 3 - Determining the Critical Path 6 weeks 3 weeks 5 weeks

50. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 50 What if the Minimum Schedule is Too Long? You must find a way to cut the schedule Begin with tasks on the critical path – Try to divide them into smaller tasks that can be done simultaneously – Assign more resources so you can do them faster Note that when you do this you might create a different critical path

51. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 51 Developing a PERT Chart Step 4 - Resource Requirements Determine the resource requirements of each task: – Equipment, Facilities, etc. – Key personnel – Total labor effort (staff days, etc) – May also show minimum and maximum reasonable allocations, i.e., 8 staff weeks: minimum 2 weeks (4 people) maximum 8 weeks (1 person)

52. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 52 Resources Write this information on the index card or post-it-note Vary labor totals or types of personnel assigned to different tasks in order to meet schedule needs 8 staff weeks: 2 weeks, 4 people 8 staff weeks: 4 weeks, 2 people 8 staff weeks: 2 weeks, 3 senior people These options may reduce the critical path or even remove this task from the critical path These options may reduce the critical path or even remove this task from the critical path

53. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 53 Scheduling Tools can... … find critical path/shortest schedule … find minimum and total effort levels … do simulation of schedule to determine likely outcomes when exact duration are indefinite

54. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 54 Scheduling Tools can … (continued) … assist in “what if” analysis of possible alternatives … revise schedules with minimal effort Sample tools: Microsoft Project®, Primavera®

55. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 55 “Schedule from the Back” concept Minimal execution times for each task Assuming adequate staff, task E must be started at least 7 weeks before final integration, whereas task A must be started at least 11 weeks before! Using PERT Charts to Decide on Development Sequence Final Integration 4 weeks C 1 week D 3 weeks F 4 weeks E 2 weeks B 6 weeks A 2 weeks

56. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 56 Suggested Notation for Post-it Notes Yellow – Normal Tasks Pink or Red – External Tasks that You Depend On Blue – External Tasks that Depend on You

57. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 57 Schedule for Project P (sample) JFMAMJJASOND

58. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 58 Gizmo hardware must arrive by June 1 – We must watch their schedule Joe and Mary must be available 100% for this project Integration must wait until Sept 15 Programmers must be available on March 1 At least three test sets must be available during the month of August Critical Dependencies, Issues, Assumptions, and Lessons Learned (sample)

59. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 59 Gantt Charts

60. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 60 GANTT Charts These are devised from some of the same data used in a PERT chart, but show the relative time phasing of the tasks instead of the dependencies Each “activity” box is sized to be proportional to the length of time it takes The boxes are lined up, usually in the order of execution, to show what is happening at what time

61. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 61 Sample Gantt Chart Vertical line represents current date Task 2 Task 3 Task 6 Task 5 Task 1 Task 7 Task 4

62. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 62 A More Advanced Form of Gantt Chart Height of box indicates number of people working on the activity Width of box indicates length of activity Task 2 Task 1 Task 3

63. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 63 Task 6 Task 5 Task 7 Does Task 6 depend on Task 5? Can Task 5 finish on time? Gantt Chart does NOT tell you... … task dependencies … significance or impact of schedule slips … whether it is realistic to expect you to meet the schedule … critical path

64. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 64 Network Charts

65. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 65 JanFebMarAprMayJunJulAug Network Chart -- Combining the Pert and Gantt Horizontal width indicates schedule length Arcs indicate dependencies Horizontal position indicates scheduled time and task parallelism Task A Task C Task B Task D Task E

66. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 66 Network Chart Summary Tells you the duration of tasks and their interdependencies. Shows Critical Path Can be color coded to show different parts of the project – Software in blue, mechanical in red, etc. But it still cannot tell you if the schedule is realistic

67. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 67 Possible Exam Questions  Explain the Advantages and Drawbacks of PERT charts and GANTTcharts  Discuss how a Network Chart combines the advantages of PERT and GANTTcharts

68. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 68 Possible Exam Questions (continued)  Discuss what information is NOT shown by a PERT chart  Discuss what information is NOT shown by a GANTTchart  Discuss what information is NOT shown by a Network chart

69. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 69 Project Management and Scheduling Tools Most such tools can show a PERT or GANTT chart More capable tools will show a network chart, which is hard to do by hand But tools take a lot of work to enter data and the data changes a lot in the early steps of detailed scheduling

70. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 70 Recommendations Regarding Management/Scheduling Tools Do a PERT chart by hand and work through the fundamental relationships Then use a tool after things have settled down Select a tool carefully – Some cannot handle the complexity of a very large project – But the most capable tools are harder to use

71. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 71 Using Network or Pert Charts to Establish a Schedule Earliest Completion Date – Tells you how soon you can complete – Tells you the earliest you can start each task Latest Start Date – Tells you how late you can start and still meet the deadline – Tells you the latest you can start each task

72. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 72 Using Network or Pert Charts to Establish a Schedule (continued) Critical Chain Analysis – Adds analysis of critical resource needs – Can help you manage to meet short cycle time

73. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 73 Earliest Completion Date A, C, E, F can slip without hurting schedule E 4 weeks Final Integration 4 weeks G 3 weeks D 6 weeks A 3 weeks B 4 weeks C 2 weeks F 2 wks 17 weeks min. Earliest Start Date Later Start Date

74. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 74 Latest Start Date A, C, E, F can start late without hurting schedule B, D, G, Final must start as shown, since on critical path Final Integration 4 weeks G 3 weeks D 6 weeks A 2 weeks B 4 weeks C 2 weeks F 2 wk E 4 weeks 17 weeks min. Earlier Start Date Latest Start Date

75. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 75 Critical Chain Analysis & Slack Management

76. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 76 A Critical Resource is a resource that is required 100% on each of two or more tasks – A piece of equipment – An individual with unique skills A critical resource can usually be used by only one task at a time If shared, each task gets only part time use ? You are essential to my project My project will fail without you Critical Resources

77. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 77 If two tasks need a resource, one must give it up or both must run slower But it is tempting to fantasize that you can share resources without such high waste Sharing a Resource Means Less Efficiency Percent UseAvailabilityWaste 100%85%15% 50%+50%40%+40%20% 33%+33%+33%25%+25%+25%25% 25%+....17.5%+....30%

78. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 78 Using Critical Resources If the resource is critical, it is also known as a constraint The fundamental rule of constraint management is that you should maximize the efficiency of the constraint Which means you should avoid overusing constraints and wasting time on inefficient sharing

79. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 79 If Task B needs a resource that is also needed by Task A then Task B is on the Critical Chain The Critical Chain The critical chain consists of all tasks using resources that are needed on the critical path Task A Task C Task B Task D Task E

80. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 80 Critical Chain Analysis Start with Latest Start Date schedule Mark critical path tasks as “on the critical chain” & identify resources needed for these tasks

81. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 81 Critical Chain Analysis (continued) If also needed elsewhere in parallel tasks, mark those tasks as “critical chain” tasks Reschedule those tasks earlier, so there is no conflict of resources This may change the critical path!

82. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 82 Conventions for Critical Chain Analysis Conflict Earlier Start Date Latest possible Start Date Normal Tasks Critical Path and Critical Chain but Not Critical Path Critical Path Tasks

83. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 83 Example of Critical Chain Analysis G and F need the same critical resource So F and its predecessors (E, C) must be started sooner A 3 weeks Final Integration 4 weeks G 3 weeks D 6 weeks B 4 weeks E 4 weeks C 2 weeks F 2 wk 17 weeks min.

84. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 84 A Further Example A and C cannot proceed in parallel This changes the critical path and lengthens the schedule! H 4 wks G 3 wks A 3 wks E 4 wks C 2 wks F 2 wks B 4 wks D 6 wks 18 weeks minimum Suppose A and C need the Same Critical Resource

85. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 85 Other Schedule Management Techniques Do more careful monitoring of critical path and critical chain tasks Start critical chain tasks as soon as you can - to provide maximum risk control DO NOT allow people to include slack time in their task schedules. All slack should be held in reserve by a higher level manager

86. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 86 Example of Slack Management Problem Final Integration 4 weeks G 3 weeks E 4 weeks C 2 weeks Final Integration 4 weeks G 3 weeks E 4 weeks C 2 weeks Plan: C and E allow slack to reduce risk Actual: C and E wait until last possible minute to start

87. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 87 What Might Really Happen Final Integration 4 weeks G 5 weeks E 4 weeks C 2.5 weeks Reality: C and G slip a little bit … C’s slip is absorbed by E’s slack But G’s slip causes the whole project to slip 2 weeks

88. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 88 Slack Management Final Integration 4 weeks G 5 weeks E 4 weeks C 2.5 weeks Actual - Slack can be applied to any task that slips, so the project stays on schedule Plan: C and E have no slack Final Integration 4 weeks G 3 weeks E 4 weeks C 2 weeks Slack - 4 wks

89. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 89 Negotiating

90. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 90 Detailed Planning Process Estimate Size Estimate Effort and Cost Estimate Schedule Evaluate Source Information Statement of Work Requirements Constraints Standards Processes History etc. WBSSize Effort & Cost Schedule OK Complete Detailed Planning Revise & Negotiate Not OK

91. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 91 If the Plan is Not Feasible DO examine assumptions and data – initial cost estimates are often very conservative Do examine risk/cost tradeoffs to see if you can accept a higher risk Do make a list of barriers that must be removed in order to make the estimate fit the constraints

92. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 92 “The quickest way to make a project uneconomical is by doubling the resources needed and using the cover story that you need to prevent failures.” Adams, The Dilbert Principle If the Plan is Not Feasible DO NOT “cave in” & lower everything to meet a target cost or schedule

93. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 93 The Negotiation Process We MUST have the lowest bid!!! We will, boss!!! Management will try to trim the budget by sending an army of low-ranking, clueless budget analysts to interview you and ask “insightful” questions. Adams, The Dilbert Principle

94. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 94 Re-think key factors Spreadsheet for estimating This will never satisfy the cost goal!???!

95. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 95 Identify Opportunities and Barriers Barriers Opportunities to Cut

96. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 96 Negotiate If they will cut back on the reviews and... Well, I’ll think about it

97. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 97 Beware... Estimates are Never Perfect

98. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 98 Estimating Accuracy vs. Phase 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 FeasibilityPlansDesignDetailed Design Code and Test Release Upper Limit Actual Lower Limit Typical Estimates

99. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 99 Some Opportunities to Offer Plan to re-estimate after important milestones Prioritize requirements and promise to deliver the top ones by the deadline – Incremental deliveries

100. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 100 Some Opportunities to Offer (continued) Put a high cost on requirements changes Look at each “adjustment factor” in Cocomo as an opportunity Get training for everyone

101. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 101 Some Typical Barriers to Faster Schedule or Lower Cost Lack of adequate resources – Software, tools, people, etc. Slow approval cycles for required resources Poor coordination with other disciplines, other companies, etc. Customers, peers in other disciplines, and managers who don’t understand software development very well

102. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 102 Some Difficult Barriers to Faster Schedule or Lower Cost Irascible and irrational customers & managers Intentional barriers – Competitors, etc – Political constraints

103. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 103 Negotiating Tip... The more facts you have, the better off you are during negotiation Get them to review your estimate – Sometimes they don’t bother Be well prepared to explain it

104. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 104 Several Iterations are Likely Identify the factors that affect the cost and schedule – Experience levels, stability levels, etc. Examine sensitivity of the results to various factors Examine historical data to make a better picture of probable events Don’t put too much faith in the accuracy of models That’s why you should use a spreadsheet!

105. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 105 Summary - I Optimal schedule depends on many factors unique to the project “Bottom up” scheduling uses PERT, GANTT, and Network charts. Basic PERT chart shows dependency & flow only Adding task duration shows critical path and shortest possible schedule length - but not relative timing

106. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 106 Summary - II Critical path analysis identifies what tasks must be shortened to shorten the overall schedule Adding resource requirements enables you to decide on sequencing and when to schedule tasks and resources GANTT shows relative timing but not dependencies, flow Network chart shows both, but requires a more capable tool

107. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 107 Summary - III Critical Chain shows resource conflicts between critical path tasks and other tasks Critical Resources must be managed to avoid impact on critical path Critical Chain Analysis shows which tasks must be started earlier in order to avoid resource conflicts Slack Management gives maximum risk control and shortest cycle time

108. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 108 Summary - IV When the plans show that there is not enough time or money to do the job, NEGOTIATE - don’t CAPITULATE Having the facts will help you in the negotiation process Expect several iterations

109. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved References 1) Brassard, Michael, The Memory Jogger Plus+, Goal/QPC, Methuen MA, 1989. 2) Goldratt, Eliyahu M. & Jeff Cox, The Goal, (North River Press, 1984.) Also Theory of Constraints and It’s Not Luck. 3) Thayer, Richard H., ed., Software Engineering Project Management, IEEE Computer Society Press, 1994. 4) U. of West Florida, PERT Home page, http://www.uwf.edu/~coehelp/studentaccounts/rn ew/perthome.html

110. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 110 End of Chapter 7

111. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 111 Addendum How to Develop a More Detailed PERT

112. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 112 Developing a Detailed PERT Top Down Approaches Start with top level process for each major activity -- draw PERT based on known dependencies An activity with more complex dependencies PrototypeFinal DesignBuildDesign Customer Assessment Marketing Review A simple activity with linear dependencies PrototypeFinal DesignBuildDesign Keyboard

113. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 113 Developing a PERT from the Top Down (continued) Then, for each process step, decompose into sub-activities PrototypeFinal DesignBuildDesign Keyboard..... Select Components Design Interfaces..... At each level, determine dependencies between the subactivities at that level

114. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 114 At Lower Levels there are Two Options 1) Limit dependencies at each level to those within that level...

115. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 115 A More Powerful Option 2) Flow dependencies down from higher level and determine dependencies between tasks at the same level from different higher level activities. I.e., determine all dependencies with other tasks, regardless of whether they are part of your activity or someone else’s......

116. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 116 Developing a PERT from the Bottom Up At the bottom level, determine all dependencies with other tasks, regardless of whether they are part of your activity or someone else’s Note that you are only determining dependencies related to your specific activity.....

117. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 117 Developing a PERT from the Bottom Up (continued) Do the same for other activities (or the people in charge of them should do this).....

118. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 118 Developing a PERT from the Bottom Up (continued) Then move up a level and coalesce dependencies from lower level tasks.....

119. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 119 Developing a PERT from the Bottom Up (continued) Continue this until you get to the top Then you will have a complete list of task dependencies

120. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 120 Developing a PERT from the Bottom Up (continued) NOTE: Many PERT tools do not support dependencies at the lower levels except within a given higher level activity. For these cases you must determine the higher level dependencies between activities by hand - (and could miss some of them as a result)

121. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 121 Alternative Bottom-up Approach Start with bottom level tasks Determine all dependencies Decide which ones to group together based on logical dependency flows, strong dependencies Move up a level and repeat Continue until you get a comfortable “top level” map

122. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 122 Alternative Bottom-up Approach NOTE: this approach may produce surprising results - combining things that did not seem appropriate to combine -- it is sometimes a good way to define teams on the project as well

123. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 123 Sample Result

124. January 20, 2000 CSE 7315 - SW Project Management / Chapter 7 - Detailed Planning - Sch. Est. & Negotiating Copyright © 1995-2000, Dennis J. Frailey, All Rights Reserved Slide # 124 Iterate the Process Whether you go bottom up or top down, your initial results may identify problems, inconsistencies, impossibilities, and unknowns that need to be resolved Resolution will result in redoing the PERT For that reason, a good tool is recommended to automate the process NOTE: normally you will not iterate the basic PERT, but will iterate a more complete PERT after developing the more advanced forms of PERT described in the next several slides