Opps approch of software development
- 1. Object-OrientedObject-Oriented Approach/DevelopmentApproach/Development of Softwareof Software Presented by: Raja PrasadPresented by: Raja Prasad Mca (IV sem) AGIMca (IV sem) AGI
- 2. OutlinesOutlines Historical ProspectiveHistorical Prospective MotivationsMotivations Object-Oriented ModelObject-Oriented Model Object-Oriented programmingObject-Oriented programming Life CycleLife Cycle Object-Oriented AnalysisObject-Oriented Analysis UmlUml Object-Oriented DesignObject-Oriented Design
- 3. Historical PerspectiveHistorical Perspective Was initially thought of as a “research curiosity”Was initially thought of as a “research curiosity” Object-oriented programming is today whatObject-oriented programming is today what structured programming was in the 1970’sstructured programming was in the 1970’s The Object and object attribute idea firstThe Object and object attribute idea first conceived in the 1950’s for A.I.conceived in the 1950’s for A.I. The real movement began in 1966 with theThe real movement began in 1966 with the introduction of theintroduction of the SimulaSimula languagelanguage
- 4. Historical PerspectiveHistorical Perspective Palo Alto Research Center (PARC) developedPalo Alto Research Center (PARC) developed SmalltalkSmalltalk in the early 1970’sin the early 1970’s SmalltalkSmalltalk is considered the first truly object-orientedis considered the first truly object-oriented languagelanguage Led other languages to support object-orientedLed other languages to support object-oriented programmingprogramming examples:examples: Objective-C, C++, Self, Eiffel,Objective-C, C++, Self, Eiffel, andand FlavorsFlavors 1980 Booch pioneered the concept of object-1980 Booch pioneered the concept of object- oriented design (OOD)oriented design (OOD)
- 5. MotivationMotivation Benefits are Greater:Benefits are Greater: ProductivityProductivity ReliabilityReliability MaintainabilityMaintainability ManageabilityManageability
- 6. MotivationMotivation Direct mapping of concepts in the problemDirect mapping of concepts in the problem domain to software units and their interfacesdomain to software units and their interfaces Viewing the world as objects is more naturalViewing the world as objects is more natural since it is closer to the way humans thinksince it is closer to the way humans think Objects are more stable than functions…Objects are more stable than functions… Supports information hiding, data abstraction,Supports information hiding, data abstraction, and encapsulationand encapsulation Easily modified, extended, and maintained…Easily modified, extended, and maintained… if your product was designed correctlyif your product was designed correctly
- 7. Object-Oriented ModelObject-Oriented Model A “new” way of thinking about what it means toA “new” way of thinking about what it means to compute and how information can be structuredcompute and how information can be structured Systems are viewed as cooperating objects thatSystems are viewed as cooperating objects that encapsulate structure and behavior in aencapsulate structure and behavior in a hierarchical constructionhierarchical construction Functionality achieved by messages passingFunctionality achieved by messages passing between objectsbetween objects
- 8. Object-Oriented ModelObject-Oriented Model Object-oriented model can be viewed as the frameworkObject-oriented model can be viewed as the framework containing:containing: AbstractionAbstraction EncapsulationEncapsulation ModularityModularity HierarchyHierarchy ConcurrenceConcurrence ReusabilityReusability ExtensibilityExtensibility
- 9. Object-Oriented ModelObject-Oriented Model The integration ofThe integration of procedural and data-procedural and data- driven approachesdriven approaches
- 10. Object Oriented ProgrammingObject Oriented Programming Concepts:Concepts: Programs are organized into cooperating collectionsPrograms are organized into cooperating collections of objectsof objects Object: entity that encapsulates state and behavior.Object: entity that encapsulates state and behavior. An instance of a classAn instance of a class Interface or protocol: set of messages to which it willInterface or protocol: set of messages to which it will respondrespond Response can be a message or routine, or delegationResponse can be a message or routine, or delegation of the message to another objectof the message to another object
- 11. Object Oriented ProgrammingObject Oriented Programming
- 12. Life CycleLife Cycle If it is accepted that object-oriented is more thanIf it is accepted that object-oriented is more than object-oriented coding, then a whole newobject-oriented coding, then a whole new approach, including life cycle, must be adoptedapproach, including life cycle, must be adopted (Booch, 1994)(Booch, 1994)
- 13. Life CycleLife Cycle Waterfall consists of aWaterfall consists of a sequential process,sequential process, primarily in oneprimarily in one directiondirection Does notDoes not accommodate realaccommodate real iterationiteration Criticized for placingCriticized for placing no emphasis on reuseno emphasis on reuse and having noand having no unifying model tounifying model to integrate the phasesintegrate the phases
- 14. Life CycleLife Cycle Water fountain lifeWater fountain life cycle describes thecycle describes the inherent iterative andinherent iterative and incremental qualitiesincremental qualities of object-orientedof object-oriented developmentdevelopment Prototyping andPrototyping and feedback loops arefeedback loops are standardstandard
- 15. Object-Oriented AnalysisObject-Oriented Analysis Examines requirements from the perspective ofExamines requirements from the perspective of the classes and objects found in the vocabularythe classes and objects found in the vocabulary of the problem domainof the problem domain Yields black-box objects that are derived fromYields black-box objects that are derived from the problem domainthe problem domain Scenarios can be used to determine necessaryScenarios can be used to determine necessary object behaviorobject behavior
- 16. Analysis exampleAnalysis example Problem: Drawing shapesProblem: Drawing shapes Scenarios:Scenarios: Draw a pointDraw a point Draw a lineDraw a line Draw a circleDraw a circle Draw a squareDraw a square Draw a rectangleDraw a rectangle Draw a polygonDraw a polygon
- 17. UMLUML UML is a standard language for specifying,UML is a standard language for specifying, visualizing, constructing, and documenting thevisualizing, constructing, and documenting the artifacts of software systems.artifacts of software systems. UML was created by Object ManagementUML was created by Object Management Group (OMG) and UML 1.0 specification draftGroup (OMG) and UML 1.0 specification draft was proposed to the OMG in January 1997.was proposed to the OMG in January 1997. UML stands forUML stands for UUnifiednified MModelingodeling LLanguage.anguage. UML is a pictorial language used to makeUML is a pictorial language used to make software blue prints.software blue prints.
- 18. UML Building-BlocksUML Building-Blocks There three building blocks of UML Building-Blocks Relationships Diagrams Structural Behavioral Grouping Annotational
- 19. ThingsThings Structural things: Structural things define the static part of the model. They represent physical and conceptual elements
- 21. Behavioral thingsBehavioral things A behavioral thing consists of the dynamic parts of UML models.
- 22. Grouping thingsGrouping things Grouping things can be defined as a mechanism to group elements of a UML model together.
- 23. Annotational thingsAnnotational things Annotational things can be defined as a mechanism to capture remarks, descriptions, and comments of UML model elements. Note is the only one Annotational thing available.
- 24. RelationshipRelationship Relationship is another most important building block of UML. It shows how elements are associated with each other and this association describes the functionality of an application.
- 28. Class diagramClass diagram Defn:-The class diagram is a static diagram. It represents the static view of an application. Purpose:-The purpose of the class diagram is to model the static view of an application.
- 29. Object diagramObject diagram Defn:-Object diagrams are derived from class diagrams so object diagrams are dependent upon class diagrams. Object diagrams represent an instance of a class diagram. Purpose:-The purpose of a diagram should be understood clearly to implement it practically.
- 30. Component diagramComponent diagram Defn:-Component diagrams are used to model physical aspects of a system. Purpose:-It does not describe the functionality of the system but it describes the components used to make those functionalities.
- 31. Deployment diagramDeployment diagram Defn:-deployment diagrams are used to describe the static deployment view of a system. Deployment diagrams consist of nodes and their relationships. Purpose:-Deployment diagrams are used for describing the hardware components where software components are deployed.
- 32. Use caseUse case Defn:-deployment diagrams are used to describe the static deployment view of a system. Deployment diagrams consist of nodes and their relationships. Purpose:-Deployment diagrams are used for describing the hardware components where software components are deployed.
- 35. Structure chart diagramStructure chart diagram
- 37. Object-Oriented DesignObject-Oriented Design Object focus shifts to the solution domainObject focus shifts to the solution domain Objects, their semantics, and relationships areObjects, their semantics, and relationships are identifiedidentified Implementation and iteration occurImplementation and iteration occur Jacobsen says “when details of theJacobsen says “when details of the implementation begin to show, it’s OOD”implementation begin to show, it’s OOD” In my practice: OOA is preliminary design, andIn my practice: OOA is preliminary design, and OOD is detailed designOOD is detailed design
- 38. Management IssuesManagement Issues Object-oriented development requires aObject-oriented development requires a commitment to change processes, resources, andcommitment to change processes, resources, and organizational structure.organizational structure. LOC measurements are less valuable, # ofLOC measurements are less valuable, # of classes reused, inheritance depth, number ofclasses reused, inheritance depth, number of class-to-class relationships, object coupling, totalclass-to-class relationships, object coupling, total # of classes, and class sizes are more valuable# of classes, and class sizes are more valuable and meaningfuland meaningful
- 39. Management IssuesManagement Issues Booch suggests smaller development teams, andBooch suggests smaller development teams, and cultivation of reuse expertscultivation of reuse experts Reward reuse, not LOC: build libraries andReward reuse, not LOC: build libraries and application frameworksapplication frameworks QA: review and testing activities still essential,QA: review and testing activities still essential, but timing and definition are differentbut timing and definition are different Tools: everything described exists in visualTools: everything described exists in visual studiostudio
- 40. The FutureThe Future The future is now… object-orientedThe future is now… object-oriented development is pretty standarddevelopment is pretty standard Class libraries and application frameworks (exist)Class libraries and application frameworks (exist) Transparent information access across applicationsTransparent information access across applications and environments (exists)and environments (exists) Movement will gain popularity (did)Movement will gain popularity (did)
- 42. Questions? Comments?Questions? Comments? Feel free to speak up!Feel free to speak up!