1. Component Based Software Engineering (CBSE)
Chris Sholar
CS5667

2. CBSE Emphasis
Design and construction of computer-based systems using reusable software “components”.
Goal is to create a catalog of software components that would be appropriate to use in given system requirements.
Leads to some questions…

3. Possible to construct complex systems using a catalog of reusable software components?
Can this be accomplished in a timely cost-efficient manner?
Can the programmers be convinced to use this method of reuse, rather than reinvent? (XP programming style?)
Can the catalog of components be made available to whoever needs it?

4. Why Is It Used? The stereo example Motivation
Components rather than discrete parts.
Simpler to implement once created, cataloged
Leads to more consistent product design and implementation…MS office suite.

5. The Process Who does it? Why important? Steps? Software engineers
Previous statements
Steps?
Parallel activities
Domain engineering
Component based engineering

6. Work product Is it right?
Operational software created from existing and newly developed software components
Is it right?
Uses same SQA practices applied to any SE process
Formal reviews
Specialized reviews to cover acquired components.
Testing, testing, testing.

7. Engineering CB Systems
Establish requirements the old fashioned way.
Architectural design is created
Differs from standard because team then examines requirements for possible component use.
Asks these questions:
COTS components available?
Internally developed reusable components available?
Are the interfaces from components compatible with architecture of the system?

8. Goal:
Design team attempts to modify or remove system requirements that cannot be implemented with COTS or internally created components.
If this cannot be done, the traditional method is then applied. Can be to create reusable components, or create proprietary software.

9. When Available Components Work
New SE activities
Component qualification
Component adaptation
Component composition
Component update

10. Component qualification
Do the services provided by the component meet the needs of the system?
Component adaptation
Can the component be modified to meet the needs of the system?
Component composition
The system architecture dictates the composition of the component.
Component update
When COTS are used, update becomes difficult because of third-party constraints.

11. The CBSE Process Model Adds
Incorporation into typical evolutionary process model.
Adds
Qualifications for interface
Adaptation of components
Assembles components
Updates components

12. Process Model Parallel tracks Domain engineering
Component based development
Establishes set of software components that can be reused by the software engineer
The major part of the work

14. Homework
Identify the parts of the GoL project that could be made into components for reuse.