1. 1 CS 501 Spring 2003 CS 501: Software Engineering Lecture 4 Project Management

2. 2 CS 501 Spring 2003 Administration Projects New project on Web site: Web Archiving Announcements by project teams

3. 3 CS 501 Spring 2003 OS 360 The operating system for the IBM 360 was two years late. Question: How does a project get two years behind schedule? Answer: One day at a time! Fred Brooks Jr., The Mythical Man Month

4. 4 CS 501 Spring 2003 The Aim of Project Management To complete a project: On time On budget With required functionality To the satisfaction of the client Without exhausting the team

5. 5 CS 501 Spring 2003 The Project Manager Create and maintain the schedule. Track progress against schedule. Keep some slack in the schedule (minimize risk). Continually make adjustments: Start activities before previous activity complete Sub-contract activities Renegotiate deliverables Keep senior management informed (visibility).

6. 6 CS 501 Spring 2003 Project Planning Methods Critical Path Method, Gantt charts, Activity bar charts, etc. are roughly equivalent. These methods are best when: 1. Model is updated regularly (e.g., monthly) 2. The structure of the project is well understood 3. The time estimates are reliable 4. Activities do not share resources Unfortunately, #2, #3, #4 rarely apply to software development

7. 7 CS 501 Spring 2003 Terminology Deliverable Work product that is provided to the customer (report, presentation, documentation, code, etc.) Activity Part of a project that takes place over time. Event The beginning or end of an activity. Milestone Completion of a specified set of activities (e.g., delivery of a deliverable)

8. 8 CS 501 Spring 2003 Example: The Critical Path Method An Open University Course Deliverables: 16Written texts (bound in pairs) 8Television programs 8 Radio programs 4Computer programs 1Home experimental kit (scientific calculator) 4Assignments and sample solutions

9. 9 CS 501 Spring 2003 Activity Graph An activity A dummy activity An event A milestone

10. 10 CS 501 Spring 2003 Activity Graph (part) Edit Unit 3 Print Unit 3 Revise Unit 3 Mail Unit 3 other activities START END

11. 11 CS 501 Spring 2003 Activity Graph (continued) Edit Unit 3 Typeset Unit 3 Revise Unit 3 Mail Units 3/4 other activities Edit Unit 4 Print Units 3/4 Revise Unit 4 other activities Typeset Unit 4 START

12. 12 CS 501 Spring 2003 Activity Graph (continued) START Edit Unit 3 Script TV 2 Make TV 2 Edit Unit 4 Prototype Computer 1 Program Computer 1 Document Computer 1 Mail

13. 13 CS 501 Spring 2003 Scheduling: Background PERT Program Evaluation and Review Technique introduced by the U.S. Navy in 1957 to support the development of its Polaris submarine missile program. PERT/Time Activity graph with three time estimates (shortest, most probable, longest) on each activity to compute schedules. PERT/Cost Added scheduling of resources (e.g., facilities, skilled people, etc.)

14. 14 CS 501 Spring 2003 Critical Path Method Uses Activity Graph with single time estimate for each activity to estimate, for each event: earliest start date latest start data and for each activity: slack A standard method for managing large construction projects. On big projects, activity graphs with more than 10,000 activities are common.

15. 15 CS 501 Spring 2003 Time Estimates for Activities (Weeks) 6 4 2 2 3 3 3 3 8 2 11 4 12 1 4

16. 16 CS 501 Spring 2003 Earliest Start Dates 6 4 2 2 3 3 3 3 8 2 1 1 4 12 1 4 0 1 4 17 19 23 5 25 22 17 15 8 20 23 24

17. 17 CS 501 Spring 2003 Latest Start Dates 6 4 2 2 3 3 3 3 8 2 1 1 4 12 1 11 12 14 13 15 20 2324 25 4 22 0 17 19 10 18 17 20

18. 18 CS 501 Spring 2003 Critical Path 0/00/0 1/11 12/12 12/14 4/13 15/1517/17 19/20 22/2323/24 25/25

19. 19 CS 501 Spring 2003 Slack 0/00/0 1/11 17/17 23/24 1 2 2 12/12 12/14 4/13 15/1517/17 19/20 22/23 25/25 4 8 12 32 3 4 4 3 3 6 1 1 Slack of activity = (latest start) end - (earliest start) begin - (time estimate) 10 0 00 0 0 0 9 9 2 2 2 3 1 1 1 1 5

20. 20 CS 501 Spring 2003 Estimating the Time for an Activity With experienced staff, estimating the actual time to carry out a task is usually fairly accurate, but... The little bits and pieces are underestimated The time from almost "done" to completely "done" is much longer than anticipated. (There's just one thing to tidy up. I need to put the comments into better shape. I really should get rid of that patch.) The distractions are not planned for. (My system crashed and I decided to upgrade the software. My child's school was closed because of snow. I spent the day showing visitors around.) Some things have to be done twice.

21. 21 CS 501 Spring 2003 Start-up Time On a big project, the start-up time is typically three to six months: Personnel have to complete previous projects (fatigue) or be recruited. Hardware and software has to be acquired and installed. Staff have to learn new domain areas and software (slow while learning). Clients may not be ready.

22. 22 CS 501 Spring 2003 Experience with Critical Path Method Administrative computing department at Dartmouth used the Critical Path Method for implementation phase of major projects. Experience: Elapsed time to complete projects was consistently 25% to 40% longer than predicted by model. Analysis: Some tasks not anticipated (incomplete understanding) Some tasks had to be redone (change of requirements, technical changes) Key personnel on many activities (schedule conflicts) System ZZZ (non-billable hours)

23. 23 CS 501 Spring 2003 Adding Resources to Activity Graph Each activity is labeled with resources, e.g., Number of people (e.g., 2 Java programmers) Key personnel (e.g., chief system architect) Equipment (e.g., 3 servers with specified software) Facilities (e.g., video conference center) Each resource is labeled with availability, e.g., Hiring and training Vacations Equipment availability

24. 24 CS 501 Spring 2003 Using Critical Path Method for Resources Assume every activity begins at earliest start date: In each time period, calculate: resources required resources available Identify shortage / surplus resources Adjust schedule acquire extra staff (e.g., consultants) rearrange schedule (e.g., change vacations) change order of carrying out activities The earlier that a problem is known, the easier it is to fix.

25. 25 CS 501 Spring 2003 Key Personnel In computing, not all people are equal The best are at least 5 times more productive. Some tasks are too difficult for everybody. Adding more people adds communications complexity Some activities need a single mind. Sometimes, the elapsed time for an activity can not be shortened. What happens to the project if a key person is sick or quits?

26. 26 CS 501 Spring 2003 Value of Scheduling Tools Planning discipline Identify all activities and inter-relationship Provide schedule for each resource (identify clashes) Early warning of difficulties (e.g., timing of equipment purchase) Routine updating of schedule Focus on key milestones Visibility for management Weekly staff meeting -- What did we expect to accomplish? What did we accomplish? What is expected for next week?

27. 27 CS 501 Spring 2003 Key Personnel: Schedule for Editor Earliest Start DateActivity Weeks 15-16Edit Unit 3 Weeks 17-18Edit Unit 4 Weeks 19-20Edit Unit 5 Weeks 21-22Edit Unit 6 Week 15Review draft of Unit 7 Week 17Review draft of Unit 8 Week 19Check proofs of Unit 3 Week 21Check proofs of Unit 4 Weeks 18-19Vacation

28. 28 CS 501 Spring 2003 Flexibility: Open University Example Schedule: Dates for broadcasting TV and radio programs are fixed. Printing and mailings can be accelerated if overtime is used. Functionality: The course team can decide what goes into the components of the course. Resources: The size of the course team can be increased slightly.