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