1. PVK-HT03

2. Contents Introduction Requirements Engineering Project Management
UI Design
Project Management
Software Design
Detailed Design and Coding
Quality Assurance
PVK-HT03

3. UI Design Activities Build prototype(s) Evaluate prototype(s)
Analyse the users
Are they used to computers
Have they used similar systems
Are there different user groups
Are they trained before using the system
Have they certain cultural or ethnic backgrounds ..
Choose an UI style
Command-line interface
Natural language interface
Menu-oriented interface
Question-answer dialogues
Form fill-in menus
Direct manipulation interface
WIMP interface
Windows
Icons
Menus
Pointing devices
Some combination
Build prototype(s)
Evaluate prototype(s)

4. Specific Guidelines OPEN LOOKTM Motif Microsoft ...
Three level certification by AT&T
Motif
Microsoft
...
PVK-HT03

5. GUI Toolkits Libraries with predefined “widgets” and event handling
Interviews
Java AWT
...
Visual tools (WYSIWYG)
Visual Basic
Delphi
XYZ Builder
PVK-HT03

6. Contents Introduction Requirements Engineering Project Management
Software Design
Detailed Design and Coding
Quality Assurance
PVK-HT03

7. Project Management Project Management Activities Project Scheduling
Cost Estimation
Analysis
Design
Testing
Coding
Operation and
Maintenance
Installation
Require-
ments
Requirements
Specification
Planning
PVK-HT03

8. Why Do Projects Fail? PVK-HT03 bella@cs.umu.se
Study by the Standish Group involving 350 companies from 1994/95, see [Pfleeger 98].

9. What is Project Management?
Project management encompasses all the activities needed to plan and execute a project:
Deciding what needs to be done
Estimating costs
Ensuring there are suitable people to undertake the project
Defining responsibilities
Scheduling
Making arrangements for the work
continued ...
Time limit
People
Resources
Functionalities

10. Project Management Activities
Project acquisition
Project planning
Resource assessment
Risk and option analysis
Cost estimation
Project scheduling
Work breakdown structure
Effort distribution
Resource assignment
Project tracking and control
Reporting
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11. Project Resources People Hardware and software tools Required skills
Availability
Duration of tasks
Start date
Hardware and software tools
Description
Duration of use
Delivery date
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12. Lines of communication
2 people
1 Line
3 people
3 lines
5 people
10 lines
n people
n(n-1)/2 lines
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13. Risks and Option Analysis
What is a risk?
Compare different development alternatives
Evaluate their risks
Select best alternative
Tools
Polar graph
Decision tree
Forms
...
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14. Polar Graphs Alternative A Reliability Schedule Alternative B
Alternative C
Reuse
Cost
Portabilty
Efficiency
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15. Analysis Example Alternative A B C Relative efficiency 0.8 1 0.6 Tools
investment
Schedule
(years) 2
1.3
Staff
utilization
(%) 85 70
100
Risk
0.75
0.9
Cost
(SEK)
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16. Analysis Example (Polar Graph)
Staff
utilisation
Schedule
Efficiency
Cost
Tools
investment
Risk
Alternative A
Alternative B
Alternative C
0.5
1 y
5 M 1
100%
250K
2 y
500K
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17. Analysis Example (Forms)
Objectives
Constraints
Alternatives
Risks
Risk resolution
strategy
Results
Plans
Commitment
Develop a software components catalogue
Within one year
Must support all existing component types
Must cost less than 1 MSEK
Buy existing information retrieval (IR) software
Buy a database and develop the catalogue using the query language
Develop a special-purpose catalogue
May be impossible within the given constraints
Catalogue functionality may be inappropriate
Develop a prototype to clarify requirements
Commission a consultants report on existing IR systems
Relax the time constraints
IR systems are too inflexible
Identified requirements cannot be met
The prototype using a DBMS may be enhanced to to a complete system
Special-purpose catalogue development is not cost effective
Develop the catalogue using the existing DBMS by enhancing the
prototype and building a GUI
Fund further 12 months of development
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18. Analysis Example (Decision Tree)
Goal:
Develop
SystemX
3.8 MSEK
4.5 MSEK
2.75 MSEK
3.1 MSEK
4.9 MSEK
2.1 MSEK
4 MSEK
3.5 MSEK
5 MSEK
Build
Reuse
Buy
Contract
Simple (0.3)
Difficult (0.7)
Minor changes (0.4)
Major changes (0.6)
Simple (0.2)
Complex (0.8)
Minor changes (0.3)
Major changes (0.7)
Without changes (0.6)
With changes (0.7)
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19. 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
Assumptions on technology

20. Risk management requirements
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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21. Define Work Breakdown Structure
Activity
Major work unit
Start date
End date
Consumes resources
Results in work products (and milestones)
Project function
Continue throughout the project
Not bound to specific phases
Step 1
Step 2
Activity 1
Activity 2
Activity 3
Phase 1
Step 1
Step 2
Activity 1
Activity 2
Task 1
Task 2
Task 3
Project
Phase 2
Step 1
Step 2
Phase N
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22. 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
PERT chart (activity network/task graph)
Critical path
Project Time-line (Gantt chart)
Resource table
PVK-HT03

23. PERT Charts Program Evaluation and Review Technique Graph Compute
Nodes = activities/tasks and estimated duration
Edges = dependencies
Compute
Slack time = available time - estimated duration
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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24. Example PERT Chart
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25. Gantt charts
A Gantt chart is used to graphically present the start and end dates of each software engineering task
One axis shows time.
The other axis shows the activities that will be performed.
The black bars are the top-level tasks.
The white bars are subtasks
The diamonds are milestones:
Important deadline dates, at which specific events may occur
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26. A Gantt Chart (Project Time Line)
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27. Another Gantt Chart
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28. Cost Estimation Approach Problems: Use empirical and historical data
Decompose problem
Check for experiences/ data on sub problems
Make qualified estimations
(Make at least two independent estimates)
Problems:
What are good measures?
Do the estimates affect the result?
Does the type of software affect the result?
Does the project environment affect the result?
...
Use empirical and historical data
Algorithmic cost modelling
COCOMO (based on LOC)
FP (based on function points)
PVK-HT03

29. COCOMO Constructive Cost Modelling [Boehm 81]
Based on publicly available historical data of 63 TRW projects
Basic assumptions:
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
Basic model: Effort = a (KDSI)b
KDSI = Kilo Delivered Source Instructions ( LOC - comments)
The a and b factors vary depending on the type of project
Effort is measured in PM (Person Months = 152h of work)
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30. COCOMO Intermediate Model
Takes into account 15 cost drivers, which are ranked on a scale from very low to extra high
Product attributes (e.g. required reliability)
Hardware attributes (e.g. main storage constraints)
Personnel attributes (e.g. language experience)
Project attributes (e.g. tools usage)
Effort=a (KDSI)b  Ci
Ci  [ ]
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31. Intermediate COCOMO Summary
Works quite well in practice
TRW data is publicly available
Needs KLOC as input
Problems:
Estimating KLOC in early project stages
Comparison of projects using different LOC counts
Outdated metrics base (70s)
Solutions:
Cross-check using an other estimation technique
Standardised LOC counts
Continuos model calibration
PVK-HT03

32. COCOMO II Main objectives of COCOMO II:
To develop a software cost and schedule estimation model tuned to the life cycle practices of the 1990’s and 2000’s
To develop software cost database and tool support capabilities for continuous model improvement
PVK-HT03

33. Schedule Estimate [ ] [ ] ( ) = Schedule Effort æ ö Effort = ç ÷ Size
Environment [ ] ( )
Factors
Scale
Process
Effort = ç ÷
Size ç ÷ è
Multiplier s ø
Environment: Product, Platform, People, Project Factors
Process: Constraint, Risk/Architecture, Team, Maturity Factors ( ) [ ]
Effort ( )
Factors
Scale
Process
Schedule =
Multiplier
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34. Stages of development Application Composition: Early Design Model:
prototyping to resolve high-risk user interface issues
2 environment drivers, 0 process drivers
Sizing in Object Points
Early Design Model:
to explore alternative architectures and concepts
7 environment drivers, 5 process drivers
Sizing in Function Points or SLOC
Post Architecture Model:
development has begun
17 environment drivers, 5 process drivers
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35. COCOMO II Model Stages Overestimated Underestimated4x
Overestimated 2x
Early Design
(13 parameters)
1.5x
1.25x
Relative
Size Range x
0.8x
Post-Architecture
0.67x
(23 parameters)
0.5x
Underestimated
Applications
Composition
(3 parameters)
0.25x
Product
Detail
Concept of
Rqts.
Design
Design
Accepted
Operation
Spec.
Spec.
Spec.
Software
Feasibility
Plans
Product
Detail
Devel.
and
Design
Design
and Test
Rqts.
Phases and Milestones

36. COCOMO and COCOMO II
The exponent value b in the effort equation is replaced with a variable value based on five scale factors rather then constants
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.
PVK-HT03

37. 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
What the software must do from the user’s perspective
Irrespective of software construction
Based on five function types:
Inputs
Outputs
Inquiries
Logic Files
Interfaces
PVK-HT03

38. Project plan contents Documentation plan Project scope
Data management plan
Resource management plan
Test plan
Training plan
Security plan
Risk management plan
Maintenance plan
Project scope
Project schedule
Project team organization
Technical description of system
Project standards and procedures
Quality assurance plan
Configuration management plan
PVK-HT03

39. 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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