Project Management

1
Project Management
2
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
3
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
4
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).
5
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
6
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)
7
Example The Critical Path MethodAn Open
University Course
Deliverables 16 Written texts (bound in
pairs) 8 Television programs 8 Radio
programs 4 Computer programs 1 Home experimental
kit (scientific calculator) 4 Assignments and
sample solutions
8
Activity Graph
An activity A dummy activity An event A milestone
9
Activity Graph (part)
Print Unit 3
Revise Unit 3
other activities
Edit Unit 3
Mail Unit 3
END
START
10
Activity Graph (continued)
Revise Unit 3
other activities
Edit Unit 3
Typeset Unit 3
Print Units 3/4
Mail Units 3/4
START
Typeset Unit 4
other activities
Revise Unit 4
Edit Unit 4
11
Activity Graph (continued)
Script TV 2
Make TV 2
Edit Unit 3
START
Mail
Edit Unit 4
Document Computer 1
Program Computer 1
Prototype Computer 1
12
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.)
13
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.
14
Time Estimates for Activities (Weeks)
4
1
3
6
2
3
1
1
12
3
12
2
3
2
8
4
4
15
Earliest Start Dates
1
4
1
5
3
2
6
17
12
23
3
20
1
12
23
1
0
3
15
12
2
3
2
19
12
8
4
8
4
4
16
Latest Start Dates
11
4
19
1
3
6
2
12
15
3
1
10
12
23
24
25
1
3
12
18
2
3
2
20
14
8
4
22
4
13
17
Critical Path
1/11
12/12
15/15
17/17
25/25
22/23
23/24
0/0
12/14
17/17
19/20
4/13
17/17
18
Slack
Slack of activity (latest start)end -
(earliest start)begin - (time estimate)
4
10
10
1
12/12
15/15
17/17
6
2
25/25
3
2
3
0
0
22/23
23/24
3
0
12
1
0
1
1
1
12
1
12/14
17/17
19/20
3
2
3
2
1
2
0
5
2
8
4
9
0
17/17
4/13
4
9
19
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.

20
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.
21
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)
22
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
23
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.
24
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?
25
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?

26
Key Personnel Schedule for Editor
Earliest Start Date Activity Weeks 15-16 Edit
Unit 3 Weeks 17-18 Edit Unit 4 Weeks
19-20 Edit Unit 5 Weeks 21-22 Edit Unit
6 Week 15 Review draft of Unit 7 Week
17 Review draft of Unit 8 Week 19 Check
proofs of Unit 3 Week 21 Check proofs of Unit
4 Weeks 18-19 Vacation
27
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.