1. Software Engineering Management
Lecture 1
The Software Process

2. Software Process Fundamental Assumption:
Good processes lead to good software
Good processes reduce risk

3. Risk Management What can go wrong in a software project?
How can the risk be reduced?

4. The Software Process (Simplified)
Feasibility and
Planning
Requirements
Design
Operation and
Maintenance
Implementation

5. The Waterfall Model Requirements Definition System and Software design
Programming
and Unit Testing
Integration and
System Testing
Operation and
Maintenance

6. Requirements Analysis and Definition
The system's services, constraints and goals are established by consultation with system users. They are then defined in a manner that is understandable by both users and development staff.
This phase can be divided into:
 Feasibility study (often carried out separately)
 Requirements analysis
 Requirements definition
 Requirements specification

7. System and Software Design
System design: Partition the requirements to hardware or software systems. Establishes an overall system architecture
Software design: Represent the software system functions in a form that can be transformed into one or more executable programs
 Unified Modeling Language (UML)

8. Programming and Unit Testing
The software design is realized as a set of programs or program units. (Written specifically, acquired from elsewhere, or modified.)
Individual components are tested against specifications.

9. Integration and System Testing
The individual program units are:
 integrated and tested as a complete system
 tested against the requirements as specified
 delivered to the client

10. Operation and Maintenance
 Operation: The system is put into practical use.
 Maintenance: Errors and problems are identified and fixed.
 Evolution: The system evolves over time as requirements change, to add new functions or adapt the technical environment.
 Phase out: The system is withdrawn from service.

11. Discussion of the Waterfall Model
Advantages:
 Process visibility
 Dependence on individuals
 Quality control
 Cost control
Disadvantages:
Each stage in the process reveals new understanding of the previous stages, that requires the earlier stages to be revised.

12. Feedback in the Waterfall Model
Requirements
Definition
System and
Software design
Programming
and Unit Testing
Integration and
System Testing
Operation and
Maintenance

13. Iterative Refinement (Evolutionary Development)
Concept: Initial implementation for user comment, followed by refinement until system is complete.
 Vaporware: user interface mock-up
 Throw-away software components
 Dummy modules
 Rapid prototyping
 Successive refinement

14. Iterative Refinement Requirements Evaluation Implementation
(prototype)
Design

15. Iterative Refinement Concurrent Activities Initial Version
Requirements
Outline
Description
Intermediate
Versions
Design
Implementation
Final
Version

16. Iterative Refinement & Software Process
Concurrent
Activities
Outline
Description
Requirements
Design
Implementation
Final
Version

17. Observations about Software Processes
Completed projects should look like the Waterfall Model
but ... the development process is always partly evolutionary.
Risk is lowered by:
 Prototyping key components
 Dividing into phases
 Following a visible software process
 Making use of reusable components

18. Feasibility Study
Before beginning a project, a short, low-cost study to identify
• Client
• Scope
• Potential benefits
• Resources needed:
staff, time, equipment, etc.
• Potential obstacles
Where are the risks? How can they be minimized?

19. Feasibility Study A feasibility study leads to a decision: go ahead
do not go ahead
think again
In production projects, the feasibility study often leads to a budget request.
In research, a feasibility study is often in the form of a proposal.

20. Class Projects
What are you going to create and why?

21. The Client In this class, you have two clients:
• Your fellow students in the class
• The professor for the course
Can you satisfy them both?

22. Project Scope What are the boundaries of the team projects?
• Must be completed in fifteen weeks
• Need a prototype that demonstrates main features

23. Potential Benefits Why are you doing this project? Examples
• Create a marketable product
• Improve the efficiency of an organization
• Control a system that is too complex to control manually
• New or improved service
• Safety or security
Get a good grade in this class

24. Resources
Examples:
Staff: 3 to 5 students, with some help. How many hours per week? What skills do people have?
Time: Must be completed by end of semester, including operational prototype, documentation, presentation
Equipment and software: What special needs are there?
Client: Will the client be sufficiently available and helpful?

25. Obstacles Class Projects
Start-up time. Creating a team, scheduling meetings, acquiring software, learning new systems, ...
Business considerations. Licenses, trade-secrets, ...
Too ambitious. Nothing to show at the end of the semester.
Changing circumstances. Team members drop the class, ...
What else?

26. Good processes lead to good software Good processes reduce risk
How to Minimize Risk?
Class Projects
• Several target levels of functionality:
required, desirable, optional
• Visible software process: intermediate deliverables
• Good communication within team and with
the professor
Good processes lead to good software
Good processes reduce risk

27. Project Topic Statement
A description of your group’s project selection
• Each group needs to pick a name. Hand in one sheet that lists the group name and its members.
Each group needs to submit a project topic. This is an informal write-up that describes what the team is going to build.
• Short enough that everybody reads it
• Long enough that no important details are skipped