P RESENTATION ON C OMPONENT B ASED S OFTWARE E NGINEERING Presented by: Richard Akono Burak Çamdereli Yousef Al Sharma Volkan Ozdamar Eastern Mediterranean University

O VERVIEW 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

I NTRODUCTION 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.

W HAT IS C OMPONENT 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”

C OMPONENT C HARACTERISTICS 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

F UNDAMENTAL P RINCIPALS 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.

T ERMS & A TTRIBUTES USED IN S OFTWARE C OMPONENT M ODEL 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.

C OMPONENT B ASED S OFTWARE D EVELOPMENT 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.

L IFE C YCLE IN C OMPONENT -B ASED D EVELOPMENT Requirements analysis Software architecture selection, construction, analysis, and evaluation Component identification and customization System integration System testing Software maintenance

P HASES OF C OMPONENT DEVELOPMENT System requirements Design the component Develop the component Testing Functional or Black Box Testing, Structural or White Box Testing

M ETRIC 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.

M ETRIC 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

M ETRIC 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%

B ENEFITS 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

D IFFICULTIES 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

CBSE VS. T RADITIONAL 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.

CBSE VS. T RADITIONAL SE- CONT.. CBSE Life Cycle is shorter. CBSE is less expensive [3] CBSEWaterfall Find Select Requirements Analysis Design Adapt Test Deploy Implementation Test Release ReplaceMaintenance

C URRENT C OMPONENT T ECHNOLOGIES

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

A PPLICATIONS This emerging component development approach is being widely used in various distinct domains.

C ONCLUSION 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

T HANK Y OU