1. Software Project Management
Lecture 1
Introduction to Software Project Management

2. Overview Software engineering Software project management
Formal methods
Software Project Management

3. Software Crisis Faulty software Delay in completion time Over budgeted
Difficult to maintain software
Mention that we have less than 60 years of software development history
Software Project Management

4. Some UK projects
Home Office asylum seeker Casework system: £80m; abandoned 2001 (Siemens).
Pathway UK benefits identity card system: abandoned 1999 with £1bn losses (ICLFujitsu).
Datacentre for UK cabinet office: £85m, cancelled in 2004 (ITNET).
MRC Laboratory of Molecular Biology, FAMIS purchasing system: £55m; ‘operating failure’ (LogicaGMC).
UK e-University: £62m; abandoned 2004 (Sun, though only £20m of the full figure).
Software Project Management

5. American experience 25% of development projects are abandoned
probability of cancellation rises to 50% for largest developments
average project overshoots schedule by 50%
75% of systems are regarded as ‘operating failures’
U.S. Bureau of Labor Statistics, 1997
Software Project Management

6. Some important facts
Relative cost of the software in a system is growing
Increase in demand for software
Increase in size and complexity of software
Increase in performance of hardware
Software Project Management

7. Software Engineering An initial, loose definition:
“the establishment and use of sound engineering principles in order to obtain, economically, software that is reliable and works efficiently on real machines”
[Bauer, 1969]
Software Project Management

8. A more useful definition
“The application of scientific and engineering efforts to
1. transform an operational need into a system through
the use of an iterative process of definition, analysis,
design, test, and validation;
2. ensure the compatibility of all interfaces […];
3. integrate reliability, maintainability, disposability, […]
to meet cost, schedule, and technical performance
objectives.”
[Blanchard, 1998]
Software Project Management

9. Software Engineering Aimed at large software
Systematic and well-defined techniques, methodologies and tools
To design, code, test and maintain quality software
Within a resource constrained environment
Emphasis the difference between large software and small softwar
2. Describe a bit more details about quality software
3. The importance of constraints on resources – time, staff, etc
4. Mention the importance of formal methods
Software Project Management

10. Large Software Developed by more than one person
Effective communications are important – standards, documentation, etc
Management issues
Techniques and methodologies are useful only if automated systems can be built upon them
Software Project Management

11. Phases of Software Development
Requirements analysis and specification
Design
Coding
Testing
Installation
Maintenance
Briefly explain what is meant by each phase
2. Point out that such a classifications of phases is not unique
3. Though these phases are listed sequentially, they are overlapping and iterative
Software Project Management

12. Some important observations
Maintenance is the most expensive phase and coding is the least expensive phase
The earlier the detection of faults, the less expensive the correction of faults
Software Project Management

13. Characteristics of software
Simple and elegant mathematical representation
Logic intensive
Cannot have partial completion
Design costs are relatively expensive
Software Project Management

14. What is a project? Key characteristics of a project:
A planned activity
Specific objectives or products
Work to be carried out in several phases
Limited resources
Deadline
Large and complex
Software Project Management

15. Major differences between software products and hardware products
Progress of software development is not obviously visible
Modifications of software products are more easy and flexible
Software products are usually more complex than the hardware products in terms of development or construction cost
Software Project Management

16. Major processes in developing a software system
Feasibility study
Project planning
Project execution
Software Project Management

17. Feasibility Study
Analyze the general requirements, costs and the functionalities and services provided by the system to be developed
Aimed to determine whether a system should be developed or not
Can be viewed as a project itself
Software Project Management

18. Important factors in planning a software project
To know the nature of the system to be developed
A management information system or a control system
To know clearly the objectives and products of the project
How to evaluate the objectives and products after the completion of the project
Software Project Management

19. What is management? Management involves the following activities:
Planning
Staffing
Innovating
Directing
Monitoring
Liaising …?
Some more activities are given in the recommended textbook
Software Project Management

20. What is software project management?
Understand the characteristics of software products
Understand what is meant by a project
Understand what is meant by management
Teacher reminds the students that these three issues were covered in the previous slides.
Software Project Management

21. Common problems with software projects
Lack of quality standards and measures
Lack of measurable milestones
Difficult to make the progress visible
Poor communications
Poor documentation
Frequent changes of requirements
Over budget and late delivery of software
Software Project Management

22. Major issues of software project management to be covered
Software development models
Software size and cost estimation
Software project planning
Software risk management
Resource allocation
Standards: ISO 9000 and CMM
Performance tracking and reporting
This is in fact a list of the topics to be covered in the course
For each topic, briefly explain:
(a) what is the objective
(b) what is the content
Software Project Management

23. Major issues of software project management to be covered (cont’d)
Software project configuration management
Software project team management
Software Project Management

24. Main problems encountered with requirements and specifications
Ambiguous
Incomplete
Inconsistent
Teachers should give examples to illustrate these problems
Software Project Management

25. To overcome these problems via
Main problems encountered with requirements and specifications (cont’d)
To overcome these problems via
Formality – achieving precision
Abstraction – concentrating on essential parts
Software Project Management

26. Formal Methods Mathematically based techniques
Providing a precise and concise language
Supporting formality
Supporting abstraction
Supporting logical reasoning
May support automation
Teachers need to emphasis that a full automation is not normally supported
Teachers also need to emphasis that formal methods are not only applicable for requirements and specifications.
Software Project Management

27. Example: traffic light control
Simple 4-way crossroads
Traffic lights control each entry
Roads run North-South and East-West N
Software Project Management

28. Light == red | redamber | green | amber,
type
Light == red | redamber | green | amber,
Junction :: ns : Light ew : Light timer : Nat
value
nextLight : Light → Light
nextLight(l) is
case l of
red → redamber,
redamber → green,
green → amber,
amber → red
end,
Software Project Management

29. if ns(j) isin {amber, redamber} \/ ew(j) isin {amber, redamber}
limit : Junction → Nat
limit(j) is
if ns(j) isin {amber, redamber} \/
ew(j) isin {amber, redamber}
then 1 else 4 end,
next : Junction → Junction
next(j) is
if limit(j) ≤ timer(j)
then mk_Junction(nextLight(ns(j)), nextLight(ew(j)), 0)
else mk_Junction(ns(j), ew(j), timer(j) + 1)
end,
safe : Junction → Bool
safe(j) is ~ (ns(j) = green /\ ew(j) = green)
Software Project Management

30. Critical properties Safety: Liveness: Not both green at the same time:
G(safe(junction))
i.e. Globally (in all states), the junction is safe
Liveness:
In each direction, lights will eventually go green:
G(F(ns(junction) = green))
i.e. Globally, in the Future, North-South is green
/\ G(F(ew(junction) = green))
Software Project Management

31. Is the junction safe and live?
Safe? – depends on what state it starts in
Live? – yes
We can model check the specification to prove these.
Software Project Management

32. local junction : Junction := mk_Junction(red, red, 0) in [change]
transition_system
[T]
local junction : Junction := mk_Junction(red, red, 0) in
[change]
true ==> junction' = next(junction)
end
ltl_assertion
[safe] T |- G(safe(junction)),
[live_ns] T |- G(F(ns(junction) = green)),
[live_ew] T |- G(F(ew(junction) = green))
Software Project Management

33. Counterexample for 'safe': ======================== Step 0:
junction = mk_Junction(red, red, 0)
Step 1:
junction = mk_Junction(red, red, 1)
...
Step 4:
junction = mk_Junction(red, red, 4)
Step 5:
junction = mk_Junction(redamber, redamber, 0)
Step 7:
junction = mk_Junction(green, green, 0)
Summary:
The assertion 'safe' is invalid.
The assertion 'live_ns' is valid.
The assertion 'live_ew' located at is valid.
Software Project Management

34. What are formal methods for?
Clarify and fix requirements
Support early analysis:
Static analysis
Testing
Model checking
Proof
Provide a basis for implementation
Software Project Management

35. Specification languages
The traffic light example was written in RAISE
There are many formal methods, some general purpose, some specialised
Software Project Management

36. A good slogan You may not be able to avoid making mistakes …
But you must find them before they cost too much!
Software Project Management

37. Modelling Modern software engineering is based on making models
A formal model (eg in RAISE) supports more analysis than in informal one (eg in UML)
Increasingly, implementations will be derived from models: programmers will be obsolete
Software Project Management

38. References
Hughes, B., and Cotterell, M. (1999) Software Project Management, McGraw Hill
Dean, C.N., and Hinchey, M.G. (1996) Teaching and Learning Formal Methods, Academic Press
Sommerville, I. (2001) Software Engineering, Pearson Education.
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39. References RAISE: http://www.iist.unu.edu/raise
Dines Bjørner (2006) Software Engineering, Springer
Software Project Management