The document presents an overview of component based software engineering. It discusses what a component is, the fundamental principles of CBSE, the CBSE development lifecycle, and metrics used in CBSE. Benefits include reduced complexity and development time while difficulties include quality of components and satisfying requirements. CBSE uses pre-built components while traditional SE builds from scratch. Current component technologies discussed are CORBA, COM, EJB, and IDL. Applications of CBSE are in many domains.

1. PRESENTATION ON
COMPONENT BASED SOFTWARE ENGINEERING
Presented by:
Chaitanya Pratap Singh
MCA (4th semester)
South Asian University, New Delhi, India

2. OVERVIEW
 Introduction
 What is Component
 Component characteristics
 Fundamental Principals
 Terms & Attributes used in Software Component Model
 Component Based Software Development
 Life Cycle in CBSD
 Metric used in CBSD
 Benefits in CBSD
 Difficulties in CBSD
 CBSE vs. Traditional SE
 Current Component Technologies
 Applications
 Conclusion

3. INTRODUCTION
 CBSE embodies the “the ‘buy, don’t build’
philosophy".
 Because of the extensive uses of components, the
Component- Based Software Engineering (CBSE)
process is quite different from that of the traditional
waterfall approach.
 It emphasizes on developing new software from
pre-built components.

4. WHAT IS COMPONENT
 A component is an independent software unit that
can be composed with other components to create
a software system.
 Council and Heineman define a component as:
 “ A software element that conforms to a component
model and can be independently deployed and
composed without modification accordingly to a
composition standard”

5. COMPONENT CHARACTERISTICS
 Independent: A component should be independent
 Composable: It means that all external interactions
must take place through publicly defined interfaces.
 Deployable: A component has to be self-contained
and must be able to operate as a stand-alone entity

6. FUNDAMENTAL PRINCIPALS
 Independent Software Development:
 Large software systems are necessarily assembled
from components developed by different people.
 To facilitate independent development, it is essential to
decouple developers and users of components.
 Reusability:
 Some parts of a large system will necessarily be
special-purpose software, it is essential to design and
assemble pre-existing components in developing new
components.
 Software quality:
 A component or system needs to be shown to have
desired behavior, either through logical reasoning,
tracing or testing.

7. TERMS & ATTRIBUTES USED IN SOFTWARE
COMPONENT MODEL
 Syntax: It refers to the „grammar‟ or the rules
followed in the code as per the specific
programming language.
 Semantics: It refers to the actual meaning and
view of the components. A component is associated
with a name, an interface and the body that
includes the code.
 Composition: This relates to the construction and
working together of components.

8. COMPONENT BASED SOFTWARE DEVELOPMENT
 Component-based software development(CBSD)
approach is based on the idea to develop software
systems by selecting appropriate off-the-shelf
components and then to assemble them with a
well-defined software architecture.
 The term component-based software development
(CBD) can be referred to as the process for building
a system using components.

9. LIFE CYCLE IN COMPONENT-BASED DEVELOPMENT
 Requirements analysis
 Software architecture selection,
construction, analysis, and evaluation
 Component identification and customization
 System integration
 System testing
 Software maintenance

10. PHASES OF COMPONENT DEVELOPMENT
 System requirements
 Design the component
 Develop the component
 Testing
 Functional or Black Box Testing,
 Structural or White Box Testing

11. METRIC USED IN CBSD
 Software metrics are intended to measure
 software quality and performance
 characteristics quantitatively encountered during the
planning and execution of software development
resource
 and effort allocation, scheduling and product evaluation.
 These can serve as measures of software products
for the purpose of
 comparison,
 cost estimation,
 fault prediction and
 forecasting.

12. METRIC USED IN CBSD CONT…
 Poulin presented a set of metrics used by IBM to
estimate the efforts saved by reuse.
 Reuse Percentage measures how much of the product
can be attributed to reuse and is given as:-
 Product Reuse Percentage = (RSI / (RSI + SSI)) * 100%
 Where
 SSI= Shipped Source Instructions
 RSI= Reused Source Instructions

13. METRIC USED IN CBSD CONT…
 The second approach is a metric called Component
Reusability level (CRL) to measure particular
component‟s reuse level per application in a CBSD.
 This metric is again divided into two sub-metrics.
First is CRLLOC, which is measured by using lines
of code, and is expressed as percentage as given
as:-
 CRL LOC ( C ) = (Reuse ( C ) / Size ( C )) *100%

14. BENEFITS IN CBSD
 Management of Complexity
 Reduce Development Time
 Increased Productivity
 Improved Quality
 Reliability is increased since the components have
previously been tested in various contexts
 Maintenance costs are reduced.
 Efficiency and flexibility is improved due to the fact
that components can easier be added or replaced

15. DIFFICULTIES IN CBSD
 Development of Components
 Quality of Components is questionable
 Lack of effective software matrix
 Component Maintenance Costs
 Reliability and Sensitivity to changes
 Unsatisfied Requirements

16. CBSE VS. TRADITIONAL SE
 CBSE views the system as a set of off-the-shelf
components integrated within an appropriate
architecture.
 SE seeks to create a system from scratch(building
something without tools).
 CBSE does not have any standard development
models like UML for SE.
 CBSE is young, therefore long term maintainability
is largely unknown.
 SE can fulfill requirements more easily.
 CBSE fulfillment of requirements is based on the
available components.

17. CBSE VS. TRADITIONAL SE-CONT..
 CBSE Life Cycle is CBSE Waterfall
shorter. Find Requirements
Select Analysis
 CBSE is less
Design
expensive
Adapt Implementation
Test Test
Deploy Release
Replace Maintenance
[3]

18. CURRENT COMPONENT TECHNOLOGIES

19.  CORBA: Common Object Request Broker
Architecture
 COM: Component Object Model
 IDL: Interface Description Language
 EJB: Enterprise JavaBeans (Java APIs)

20. APPLICATIONS
 This emerging component development approach
is being widely used in various distinct domains .

21. CONCLUSION
 CBSD is an inevitable next wave solution that has
potential to improve time-to-market and man
power/cost trends that have been ongoing.
 CBSD is best implemented using more modern
software technologies like:
 COM
 JAVA
 EJB
 CORBA
 ActiveX

22. THANK YOU