S/W Project Management

1. S/W Project Management Software Project Planning (POMA) Task Analysis

2. Agenda • Software Project Planning (POMA) • Task Analysis • Work Breakdown Structure (WBS) • Task Scheduling Task Analysis & Scheduling

3. Work Breakdown Structure • Is a depiction of the project (model) in terms of the discrete pieces of work needed to complete the project and the ordering of those pieces of work. • Performed by software project team. • Focuses on the tasks required to produce the artifacts that are to be delivered. Task Analysis & Scheduling

4. Work Breakdown Structure • As the details of the software development and support process are realized subtasks are identified. • There are a number of tools used to support the WBS activity: • Graphical – MS Visio, Smartdraw, ArgoUML. • Scheduling – MS Project, Primavera TeamPlay Task Analysis & Scheduling

5. Work Breakdown Structure Steps in the WBS: • Examine the set of required external deliverables. • Identify and list the steps and tasks needed to produce the required deliverables, including intermediate deliverables. • Sequence the identified tasks required to produce the deliverable. • Estimate the effort required to perform each task. • Estimate the productivity of the resources that will be applied to the tasks. Task Analysis & Scheduling

6. Work Breakdown Structure Steps in the WBS: • Compute the time needed for each task by dividing the task effort estimates by the resource productivity estimates. • Lay out the time needed for each task and “label” each task with its task name and the assigned resources; this layout forms the initial schedule Task Analysis & Scheduling

7. FlowofWBStoschedule Identify and list all deliverables For each deliverable: Identify and list the necessary tasks for completing the deliverable Sequence the tasks Perform task For each task: Compute the timeline required by dividing effort by productivity For each task: Estimate the productivity of the assigned resources For each task: Estimate the effort needed Lay out the timeline for all the ordered tasks need for each deliverable After the timelines for all tasks for all deliverable are computed Task Analysis & Scheduling

8. WBS - Example • Deliverable 1: Executable code that is installable from a CD. • Deliverable 2: Help text, usage, and reference information that is installable from CD. • Deliverable 1 activities: • To develop code: requirements specification, and analysis (which are already completed), design, coding, and testing. • To make code installable: requirements specification (already completed), design, coding and testing Task Analysis & Scheduling

9. WBS - Example • Deliverable 2 activities: • Creating help text: requirements specification and analysis (already completed), design, writing, and testing. • Developing usage and reference information: requirements specification and analysis (already completed), design, writing, and testing. Task Analysis & Scheduling

10. WBS - Example • Choice of activities and sequence depends on: • The size and complexity of both the problem and the solution, • The process and methodology that the software organization has defined and trained its people to follow, and agreed with its client to use. • Sequencing the activities needed for the development of the artifacts can be a large problem for new software organizations. Task Analysis & Scheduling

11. WBS Task Refinement • List of activities for Deliverable 1: • Activity A: Designing and documenting the design using an agreed upon notation • Activity B: Coding (in language agreed upon) • Activity C: Defining test cases and generating test scripts • Activity D: Executing test scripts • Activity E: Correcting and fixing problems found during testing • Activity F: Collecting the tested executable modules and handing them to the packaging group Task Analysis & Scheduling

12. Refinement of activity A: Table 2.1. Subtasks within the Design activity WBS Task Refinement Task Analysis & Scheduling

13. WBS - Task Sequencing • After the tasks refinement then comes the sequencing of the tasks. • There are usually dependencies between tasks i.e., Task A-1 needs to be completed before Tasks A-2, A-3, A-4 and A-5 commence. • There may also be overlap between tasks, i.e., Task A-2 maybe or may not be started before Task A-1 is completed. Task Analysis & Scheduling

14. WBS - Task Sequencing • Sequence diagrams depict the start-stop relationships among the various subtasks. • Sequence diagram – shows all the tasks required to complete an activity and the order in which those tasks must be performed, including the depiction of the tasks that may be performed in parallel. Task Analysis & Scheduling

15. Task A-3 Task A-1 Task A-2 Task A-4 Task A-5 WBS - Task Sequencing Fig. 2.2 Sequence diagram • Tasks A-3, A-4, and A-5 maybe performed in parallel. • Note there is no indication how task may overlap. Task Analysis & Scheduling

16. WBS - Task Sequencing • Steps for the construction of the software project: • List the deliverables. • For each deliverable, list the activities that are required. • For each activity, list the set of subtasks that are required. • Further refine any of the subtasks by creating the next level of subtasks, if necessary. • Construct the sequence relationship of the subtasks • Depict the sequence relationship with a sequence diagram Task Analysis & Scheduling

17. WBS – Time and Resource Assignments • What is a “satisfactory” level of refinement? • Guidelines: • Each task may be assigned to one person. • The estimate of the task cost, stated not in terms of money but rather in terms of time required to complete it, does not extend beyond more than two or three project status meeting. • Ensuring single person accountability makes the management and tracking of the task much easier. Task Analysis & Scheduling

18. WBS – Time and Resource Assignments • Assume that project management meetings are conducted very often, daily, for a small project (range of weeks) and weekly if the s/w project is large (range of months < 1 year). Units of tasks management: • Project team must decide on a unit of measurement, usually range from 1 hour units to a several days (< week). • It is important to state hours in a day and days in a week (5 or 7) Task Analysis & Scheduling

19. WBS - Time and Resource Assignments Units of tasks management: • Time must be allocated for non-direct-task-related activities e.g., departmental meetings, telephone interruptions etc. • How to estimate time required to complete a task. • Ask experienced s/w engineers (bottom-up estimating). • Assemble a team and ask them to estimate each task in terms of some common work volume unit e.g., lines of code (LOC) per hour per day Task Analysis & Scheduling

20. Units of tasks management: Example of Historical Information WBS - Time and Resource Assignments Task Analysis & Scheduling

21. Task A-3 7 days 3 days 5 days 3 days Task A-1 Task A-2 Task A-4 2 days End 3 days Task A-5 5 days WBS - Time and Resource Assignments Fig2.3 Subtasks with estimated times. • Longest path includes A-1, A-2, and A-3 (critical path) • There is no slippage along the critical path. Task Analysis & Scheduling

22. WBS - Time and Resource Assignments Estimates and assignments: • Need to assign people to tasks. • Spmr need to consider skills required to perform each task, then seek people capable of performing these tasks. • Must consider the availability of the identified skilled people. • Must consider the timing of and the requirement of the identified person for another aspect of the project or another project. The above must be made in conjunction with the schedule in the time-estimated WBS. Task Analysis & Scheduling

23. WBS - Time and Resource Assignments Estimates and assignments cont: • The dependencies of the tasks in the WBS restrict assignment of resources, it also allows for the use of additional resources. • The skill of the team members may also restrict assignment. Task Analysis & Scheduling

24. Estimates and assignments: Subtasks with time Estimates and People Assignments WBS - Time and Resource Assignments 5 days 3 days 7 days 2 days 5 days Task Analysis & Scheduling

25. Milestones WBS - Time and Resource Assignments 5 days 3 days 7 days 2 days 5 days Minor Milestone Milestone Task Analysis & Scheduling

26. WBS - Time and Resource Assignments Milestones: • End-point of a software process activity. • A significant event in a project that occurs at a specific point in time. • The labeling of a milestone gives a certain amount of priority and significance to the event. • Spmr may use the term “milestone” to emphasize the particular activity, as well as for the purpose of recognizing the attainment of a significant task. Task Analysis & Scheduling

27. WBS - Time and Resource Assignments Milestones: • Depending on the size of the project the schedule might only be depicted in terms of milestones. Such a schedule may be used by higher level management. • It is important for the spmr to recognize the accomplishments of milestones and publicly recognize them. • The spmr should also pay attention to missed milestones. Task Analysis & Scheduling

28. Task Sequence and Effort representation • All tasks share at least two basic characteristics • Require effort in terms of person-days required to complete each task • A specified order for processing the task Task Analysis & Scheduling

29. Task sequence/effort table Total effort required: 40 person-days Task Analysis & Scheduling

30. Graphical representation of tasks from previous table Task B 5 9 Task A Task D 11 Task E 8 End 9 7 Task C Critical Task Critical Path Total project time: 35 days Non-critical Task Non-critical Path Task Analysis & Scheduling

31. Critical versus Non-Critical Paths Critical path • The path that takes the most time to complete. Critical task (critical activity) • A task that resides on the critical path. Non-critical path • Any path that is not a critical path and thus takes less effort to complete than the critical path. Non-critical task (non-critical activity) • Any activity that resides on a non-critical path and not a critical path. These tasks may accept some delay in completion. Task Analysis & Scheduling

32. Critical Path Method (CPM) “The critical path method analyses the precedence of activities to predict the total project duration. The method calculates which sequence activities (path) has the least amount of flexibility” • Quality Software Project Management, Futrell et. al. Task Analysis & Scheduling

33. Task Scheduling • Forward-pass scheduling • Early start time (ES) and early finish (EF) • Backward-pass scheduling • Late start (LS) and Late finish (LF) • Slack time Task Analysis & Scheduling

34. Forward-pass scheduling 9 9 14 9 16 16 27 27 35 Task Analysis & Scheduling

35. Backward-pass scheduling 9 0 11 16 9 16 16 27 27 35 Task Analysis & Scheduling

36. Slack time • Total slack time of an activity • The difference in start time between a non-critical task’s late start time and its early start time or its late finish time and early finish time. Total slack time of a task = LS - ES Or Total slack time of a task = LF – EF e.g., Activity B: LS – ES (11 - 9) or LF – EF (16 - 14) => 2 • Total slack time • The maximum allowable delay for all non-critical activities. Task Analysis & Scheduling

37. Program Evaluation and Review Technique (PERT) • An estimating technique • assumes each activity duration is subject to a range estimates • uses weighting method to arrive at a specific duration. Task Analysis & Scheduling

38. Program Evaluation and Review Technique (PERT) Expected estimate (EE) = [O + P + (4 x A)] / 6 Where O = most optimistic estimate P = most pessimistic estimate A = most likely estimate Task Analysis & Scheduling

39. Program Evaluation and Review Technique (PERT) Expected Project time (EPT) • Sum of expected estimates of the critical tasks. EPT = Σ(EE of all critical task) Task Analysis & Scheduling

40. CPM vs PERT • Scheduling a lot of activities with 3 estimates computationally messy • many people argue 3 estimates are not much more accurate than 1 estimate • Most project management scheduling software use CPM Task Analysis & Scheduling