Introduction to CBSE: Definitions, Concepts, and Principles

COP 4009 4th Lecture September 26, 2005

COP 4009 COP 4009 Component-Based Software EngineeringComponent-Based Software Engineering

Fall 2005Instructor: Masoud Sadjadi

http://www.cs.fiu.edu/~sadjadi/Teaching/COP-4009-Fall-2005/index.html

Introduction to CBSE:Introduction to CBSE:Definitions, Concepts, and PrinciplesDefinitions, Concepts, and Principles

Fourth Lecture on September 26, 2005 2COP-4009: Component-Based Software Engineering

AcknowledgementsAcknowledgements

Dr. George T. Heineman – This course is based on the “CS 509 Design of Software Systems -

Spring 2005” by Dr. Heineman with some adjustments to become appropriate for undergraduate students. Dr. Heineman has generously offered his course material (including the slides) and his help during preparation of this course. I am very grateful to him.

– The original slides and the course material can be found at: http://www.cs.wpi.edu/~heineman/html/teaching_/CS509/index.html

Dr. William Councill and other authors of the main textbook

Dr. Clemens Szyperski

Drs. Betty Cheng, Peter Clarke, Bernd Bruegge, and Allen Dutoit


AgendaAgenda

Component Based Software Engineering

Definitions

Component Infrastructure

Component Model

Tasks and Responsibilities


Other Engineering FieldsOther Engineering Fields

Every other engineering profession– divides problems into sub-problems

Ready-made solutions Sub-contracted to conform to specifications

– conforms to standards– self-imposed industrial regulation– certification regiment for engineers

But not Software Engineering…


Some ExcusesSome Excuses

Software is different from hardware My software needs are unique We don’t trust software written elsewhere Users can live with defective software

We want something better…


CBSE MethodologyCBSE Methodology

At its core, CBSE is a methodology that:– constructs applications from software units– supports vendors in producing reusable

software units– develops core technologies that support the

run-time execution of these units– defines agreed-upon standards– engenders trust among participants

We will participate in most of these tasks during this semester


AgendaAgenda


Definitions


Component Model



Software ComponentSoftware Component

A Software Component is a software element that conforms to a component model and can be independently deployed and can be composed without modification all above according to a composition

standard


Component ModelComponent Model

A Component Model defines specific interaction and composition standards.

An interaction standard is the mandatory requirements employed and enforced to enable software elements to directly and indirectly interact with other software elements.

Component

interface

SoftwareEntity

supply

manage

consume


comp

Interaction StandardInteraction Standard

Based on the concept of an interface– “An abstraction of the behavior of a component”

Provided interface– component implements the interface

Required interface– component interactions with other

software elements are captured

Context Dependency

in

out


Composition StandardComposition Standard

Composition– the combination of two or more software

components yielding a new component behavior

Defines several important concepts– Packaging Installing Instantiating– Deploying Configuring


CMICMI

A Component Model Implementation is the dedicated set of executable software elements required to support the execution of components that conform to the model

The “Plumbing” that enables components to connect and interact with each other


AgendaAgenda


Definitions


Component Model



Big PictureBig Picture

Decompose problem into projects and subprojects

Design logical component infrastructure

Problem to be

Solved

Problem to be

Solved

• Select suitable component model

• Provided by vendor; or, if a proprietary component model, must be implemented.

Legend

Subproject

Project

PerformanceRequirements

Evaluate Success of Software System


Master SoftwareDevelopment Plan


Increasingly detailed refinement of design leads to an implemented component infrastructure



Analyze component infrastructure from multiple viewpoints

Legend

Interaction

Component

Logical ComponentInfrastructure

Component Model Implementation



Component InfrastructureComponent Infrastructure

A software component infrastructure is – a set of interacting software components

The infrastructure is designed to ensure that a software system constructed using those components will satisfy clearly defined performance requirements


Designing a Component InfrastructureDesigning a Component Infrastructure

The Component Infrastructure is layered

Layering is a strategy for decomposing complex structures


Four LayersFour Layers

User

Workflow and Process Control

Business Services

Data and Operating System Services


UserUser

User components provide the external interface– graphical user interfaces (GUI), Web-based, or batch-

oriented

Understand user interactions

Request services from other components in response to commands issued by the user


Workflow and Process ControlWorkflow and Process Control

Workflow and process control components manage complex, automated business processes that interact with (potentially) many business services


Business ServicesBusiness Services

Business service and legacy wrapping components provide the implementation of the business rules and the operational activity

This is accomplished using internal business object implementations, or by wrapping legacy systems behind the component interface


Design Layers and DesignersDesign Layers and Designers

User

Business Services &Legacy Wrapping

Data/Operating System Services

Workflow and ProcessControl

Solution

Component Designers

Business

Component Designers

Data/Infrastructure

Component Designers

Supply

Consume

Supply Consume


AgendaAgenda


Definitions


Component Model




Interfaces

Naming

Meta data

Composition

Customization

Interoperability

Evolution Support

Packaging & Deployment

Specification of component behavior and properties

Definition of Interface Description Language (IDL)



Interfaces Naming

Meta data

Composition

Customization

Interoperability

Evolution Support


Global unique names for interfaces and components

Interface YComponent X



Interfaces

Naming Meta data

Composition

Customization

Interoperability

Evolution Support


Information about components, interfaces, and their relationships

Interfaces to services providing such information


X Meta dataY Meta data



Interfaces

Naming

Meta data Composition

Customization

Interoperability

Evolution Support


Interfaces and rules for combining components to create larger structures and for substituting and adding components to existing structures


Component Z???



Interfaces

Naming

Meta data

Composition Customization

Interoperability

Evolution Support


Interfaces for customizing components

User-friendly customization tools will use these interfaces


CustomizationAPI

Interface YComponent X’



Interfaces

Naming

Meta data

Composition

Customization Interoperability

Evolution Support


Communication and data exchange among components from different vendors, implemented in different languages

Interface Y

Component XVB Impl.

Component ZJava Impl.

???



Interfaces

Naming

Meta data

Composition

Customization

Interoperability Evolution Support


Rules and services for replacing components or interfaces by newer versions


X Meta dataVersion 1

Version 1.1

Y Meta dataVersion 1.0

Version 2.0



Interfaces

Naming

Meta data

Composition

Customization

Interoperability

Evolution Support Packaging &

Deployment

Packaging implementation and resources needed for installing and configuring a component


X Meta dataY Meta data


AgendaAgenda


Definitions


Component Model



Tasks and ResponsibilitiesTasks and Responsibilities

Component Factory– Three primary groups (AD, CD, CMID)


ApplicationDevelopment

Provides CD with component requests and designsProvides CMID with requirements for infrastructure services

ComponentDevelopment

Builds components to specification and provides to ADProvides feedback on CMI and its services

Component Model ImplementationDevelopment

Provides AD with a component model implementation that satisfies application criteria

Provides CD with suitable tools and an environment for component development


ApplicationDevelopment

Provides CD with component requests and designsProvides CMID with requirements for infrastructure services

ComponentDevelopment

Builds components to specification and provides to ADProvides feedback on CMI and its services

Component Model ImplementationDevelopment

Provides AD with a component model implementation that satisfies application criteria

Provides CD with suitable tools and an environment for component development

Introduction to CBSE: Definitions, Concepts, and Principles

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