1 Chapter 7 Project Scheduling and Tracking

2 Write it Down! SoftwareProjectPlan Project Scope EstimatesRisksSchedule Control strategy

3 Why Are Projects Late?  an unrealistic deadline  changing customer requirements  an honest underestimate of effort and/or resources  predictable and/or unpredictable risks  technical difficulties  human difficulties  miscommunication  a failure to recognize  a lack of action to correct

4 Comments on “Lateness”  Determine the estimated effort and duration  Use an incremental process model  Explain it to the customer  Offer the incremental development strategy

5 Scheduling Principles  Compartmentalization — define distinct tasks  Interdependency — indicate task interrelationship  Time allocation — assign task start & finish time  Effort validation — schedule no more than the allocated number of people  Defined responsibilities — people must be assigned  Defined outcomes — each task must have an output  Defined milestones — review for quality

6 People/Work Relationship  People/Work  Not linear  Counterproductive?  Use fewer people over a somewhat longer time span to accomplish the same objective.

7 Effort Allocation 40-50% 30-40%  “front end” activities  customer communication  analysis  design  review and modification  construction activities  coding or code generation  testing and installation  unit, integration  white-box, black box  regression 15-20%

8 Defining Task Sets  determine type of project  assess the degree of rigor required  identify adaptation criteria  compute task set selector (TSS) value  interpret TSS to determine degree of rigor  select appropriate software engineering tasks

9 Types of Project  Concept development projects  New application development projects  Application enhancement projects  Application maintenance projects  Reengineering projects

10 Adaptation Criteria  Size of the project  Number of potential users  Mission criticality  Application longevity  Stability of requirements  Ease of customer/developer communication  Maturity of applicable technology  Performance constraints  Embedded and nonembedded characteristics  Project staff  Reengineering factors

11 Task Set Selector (TSS)  Select the appropriate task set Task set selector value Degree of rigor Task set selector value Degree of rigor TSS < 1.2 casual TSS < 1.2 casual 1.0 < TSS < 3.0 structured 1.0 < TSS < 3.0 structured TSS > 2.4 strict TSS > 2.4 strict

12 Degree of Rigor  Select the appropriate task set Task set selector value Degree of rigor Task set selector value Degree of rigor TSS < 1.2 casual TSS < 1.2 casual 1.0 < TSS < 3.0 structured 1.0 < TSS < 3.0 structured TSS > 2.4 strict TSS > 2.4 strict

13 Software Engineering Tasks  Depend on the project type and the degree of rigor.  Decompose each major task into a set of subtasks.  Be Distributed on the project time line.  Flow smoothly into the next.

14Example

15 Example

16 Define a Task Network

17 Scheduling  Information  Estimates of effort  A decomposition of the product function  The selection of the appropriate process model and task set  Decomposition of task  A task network  Methods  Program evaluation and review technique (PERT)  Critical path method (CPM)

18 PERT & CPM  Determine the “critical path”  Establish “most likely time”  Calculate “boundary times”  earliest time  latest time  earliest finish  latest finish time  the total float

19 PERT

20 Timeline/Gantt Chart

21 Project Table

22 Tracking/Controlling the Schedule  Tracking  Periodic project status meeting  The results of all reviews  Project milestones  Actual start-date  Earned value analysis  Controlling  Additional resource  Redefine the project schedule  Time-boxing

23 Earned Value Analysis  Budgeted Cost of Work Scheduled (BCWS)  BCWS values for all tasks k, BAC =  (BCWS k )  Budgeted Cost of Work Performed (BCWP)  Schedule Performance Index, SPI = BCWP/BCWS  Schedule Variance, SV = BCWP - BCWS  Percent complete = BCWP/BAC  Actual Cost of Work Performed (ACWP)  Cost Performance Index, CPI = BCWP / ACWP  Cost Variance, CV = BCWP - ACWP

24 Error Tracking  DRE = E/E(E+D)  Errors per requirements specification page, E req  Errors per component -- design level, E design  Errors per component -- code level, E code  DRE -- requirements analysis  DRE -- architectural design  DRE -- Component level design  DRE -- coding

25 Milestones

26 Scheduling Process

27 Task Durations & Dependencies

28 Activity Network

29 Activity Bar Chart

30 Allocation of People to Activities

31 Staff Allocation vs. Time