Project Management
Project Management Activities
Project Scheduling
Cost Estimation
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Project Management Activities
Project acquisition
Project planning
o Resource assessment
o Risk and option analysis
Cost estimation
Project scheduling
o Work breakdown structure
o Effort distribution
o Resource assignment
Project tracking and control
Reporting
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Project Resources
People
o
o
o
o
Required skills
Availability
Duration of tasks
Start date
Hardware and software tools
o
o
o
o
Description
Availability
Duration of use
Delivery date
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Risk Analysis
What is a risk?
Risk impact: the loss associated with the event
Risk probability: the likelihood that the event
will occur
Risk control: the degree to which we can
change the outcome
Risk exposure = (risk probability) x (risk impact)
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Top Ten Project Risks
Staff deficiencies
Unrealistic schedules and budgets
Developing the wrong functions
Developing the wrong interface
Over-engineering
Changing requirements
Externally developed items
Externally performed tasks
Performance problems
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Assumptions on technology
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Define Work Breakdown
Structure
Activity
o
o
o
o
o
Major work unit
Start date
End date
Consumes resources
Results in work products
(and milestones)
Phase 1
Project
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Project function
Phase 2
Phase N
o Continue throughout
the project
o Not bound to
specific phases
Step 1
Step 2
Step 1
Step 2
Activity 1
Activity 2
Activity 3
Activity 1
Activity 2
Task 1
Task 2
Task 3
Step 1
Step 2
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Schedule Activities
Almost all activities depend on the completion
of some other activities
Many activities can be performed in parallel
Organisation necessary to balance work-load,
costs, and duration
o PERT chart (activity network/task graph)
Critical path
Project Time-line (Gantt chart)
Resource table
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PERT Charts
Program Evaluation and Review Technique
Graph
o Nodes = activities/tasks and estimated duration
o Edges = dependencies
Compute
o Slack time = available time - estimated duration
o Critical path
A path is critical when it contains an activity that, if
delayed, will cause a delay of the whole project.
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Example PERT Chart
Time-motion study of
existing hardw are
3
2d
5/4/00
5/5/00
Get final report from PSU
Design electrical and
pneumatic renovations
Schedule dow n-time w ith
production supervisor
Schedule contractor for
electrical and pneumatic
Renovate electrical and
pneumatic
Install new hardw are
1
5d
4
4d
5
2d
8
1d
13
2d
14
3d
4/27/00
5/3/00
5/4/00
5/9/00
5/10/00
5/11/00
5/12/00
5/12/00
5/17/00
5/18/00
5/19/00
5/23/00
Shut dow n production line
Remove old hardw are
10
1d
11
2d
5/12/00
5/12/00
5/15/00
5/16/00
Get blueprints for old
hardw are
Schedule truck to pickup
hardw are at PSU
Inform PSU about pickup
Transport hardw are from
PSU
Store old hardw are (just
in case)
2
1d
6
1d
7
2d
9
2d
12
10d
4/27/00
4/27/00
5/4/00
5/4/00
5/5/00
5/8/00
5/9/00
5/10/00
5/17/00
5/30/00
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Gantt charts
A Gantt chart is used to graphically present the
start and end dates of each software engineering
task
o One axis shows time.
o The other axis shows the activities that will be
performed.
o The black bars are the top-level tasks.
o The white bars are subtasks
o The diamonds are milestones:
• Important deadline dates, at which specific events may occur
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A Gantt Chart (Project Time
Line)
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Another Gantt Chart
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Cost Estimation
Approach
o Decompose problem
o Check for experiences/
data on sub problems
o Make qualified
estimations
o (Make at least two
independent estimates)
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Problems:
o What are good measures?
o Do the estimates affect the
result?
o Does the type of software
affect the result?
o Does the project environment
affect the result?
o ...
Use empirical and historical data
Algorithmic cost modelling
COCOMO (based on LOC)
FP (based on function points)
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COCOMO
Constructive Cost Modelling [Boehm 81]
Based on publicly available historical data of 63 TRW
projects
Basic assumptions:
o
o
o
o
Requirements change only slightly during the project
There is good project management
The historical data is representative
Assigning more resources to the project does NOT
result in linear decreasing development time
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Basic Model
Effort = a (KDSI)b
Schedule = c (Effort)d
•KDSI = Kilo Delivered Source Instructions ( LOC - comments)
•The a, b, c, and d factors vary depending on the type of project
•Effort is measured in PM (Person Months = 152h of work)
•Schedule is the Development Time measured in Months
Organic
In-house IS, Development in a familiar environment
Semi-detached
Between OM- and EM projects
Embedded
Large and inexperienced teams, many constraints
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a
b
c
d
2.4
1.05
2.5
0.38
3.0
1.12
2.5
0.35
3.6
1.20
2.5
0.32
Boehm, Software Engineering Economics, Prentice-Hall, 1981.
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COCOMO Summary
Works quite well in practice
Needs KLOC as input
Problems:
o Estimating KLOC in early project stages
o Comparison of projects using different LOC counts
o Outdated metrics base (70s)
Solutions:
o Cross-check using an other estimation technique
o Standardised LOC counts
o Continuous model calibration
COCOMO II is a recent new version
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COCOMO II
Goal: To develop a software cost and
schedule estimation model tuned to the life
cycle practices of the 1990’s and 2000’s
3 Models
o Application Composition: prototyping to resolve highrisk user interface issues, 2 environment drivers, 0 process
drivers, Sizing in Object Points
o Early Design Model: to explore alternative architectures
and concepts,7 environment drivers, 5 process drivers,
Sizing in Function Points or SLOC
o Post Architecture Model: development has begun, 17
environment drivers, 5 process drivers, Sizing in Function
Points or SLOC
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Effort and schedule in COCOMO 2
Effort = NOP/productivity
 NOP = OP * [(100 -%reuse)/100]
Application
Composition
Model
 Productivity = NOP/man-months, 5 productivity levels
depending on the 2 environment drivers (table 3.12 course book)
Environment
(Process Scale Factors)


=
[
]
Effort  Multipliers  Size


Environment: product, platform, people, project factors
Early Design
and Postarchitecture
Model
Process: constraint, risk/architecture, team, maturity factors
(Process Scale Factors )
(
)
=
Schedule Multiplier [Effort]
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COCOMO II Model Stages
4x
2x
Early Design
(13 parameters)
1.5x
Overestimated
1.25x
Relative
Size Range x
0.8x
Post-Architecture
(23 parameters)
0.67x
0.5x
0.25x
Concept of
Operation
Feasibility
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Phases
Underestimated
Applications
Composition
(3 parameters)
Plans
and
Rqts.
and Milestones
Detail
Design
Spec.
Product
Design
Spec.
Rqts.
Spec.
Product
Design
Detail
Design
Accepted
Software
Devel.
and Test
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COCOMO II summary
COCOMO II
+ allow for spiral model instead of waterfall model
only
+ Size of project can be listed as object points,
function points or source lines of code (SLOC)
+ The environmental multipliers are calculated from
seventeen cost drivers better suited for today's
methods
- Calibration is difficult, but can improve accuracy
by a factor of five
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Function Points
Function Point Analysis (FPA) measures the size of a
software product in terms of the functionality it
delivers to the users. A.J. Albrecht 1979
o What the software must do from the user’s perspective
o Irrespective of software construction
Based on five function types:
o
o
o
o
o
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Inputs
Outputs
Inquiries
Logic Files
Interfaces
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Project plan contents
Project scope
Project schedule
Project team organization
Technical description of
system
Project standards and
procedures
Quality assurance plan
Configuration management
plan
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Documentation plan
Data management plan
Resource management
plan
Test plan
Training plan
Security plan
Risk management plan
Maintenance plan
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Difficulties and Risks in Project
Management
Accurately estimating costs is a constant challenge
It is very difficult to measure progress and meet
deadlines
It is difficult to deal with lack of human resources
or technology needed to successfully run a project
Communicating effectively in a large project is hard
It is hard to obtain agreement and commitment
from others
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