Object-Oriented Systems Development: survey of structured methods by A G SutcliffeIntroductionOutlineObject Oriented ConceptsObject Oriented Model of SystemsEvaluation of Modeling ComponentsEvaluation of Modeling Components – Cont.Slide 8Evaluation Procedure – Conceptual ModelingEvaluation Procedure – Procedural GuidelinesEvaluation Procedure – Transformations and ProductsEvaluation Procedure – OO Meta-modelReview of Object Oriented and Traditional MethodsObject Oriented MethodsObject Oriented Methods – Hierarchical Object-Oriented Design (HOOD)Object Oriented Methods – Object-Oriented Systems Design (OOSD)Object-Oriented Systems Design (OOSD) – Object Model Structure ChartObject Oriented Methods – Object-Oriented Systems Analysis (OOSA)Object-Oriented Systems Analysis (OOSA) – Object Relationship ModelObject Oriented Methods – Object-Oriented Analysis (OOA)Object-Oriented Analysis (OOA) – Object Model in the Service LayerObject Oriented Methods – ObjectOrySummary of Object Oriented MethodsTraditional MethodsTraditional Methods – Information Engineering (IE)Traditional Methods – Information Systems Activity and change analysis (ISAC)Traditional Methods – Structured Analysis/Structured Design (SASD)Traditional Methods – Structured Systems Analysis and Design Method (SSADM)Traditional Methods – Structured Analysis and Design Techniques (SADT)Traditional Methods – Jackson System Development (JSD)Nijssen’s Information Analysis Method (NIAM)Traditional Methods – Mascot-3Summary of Traditional methods evaluationConclusionsFinal ThoughtsAdditional ReferencesQuestionsObject-Oriented Systems Development: survey of structured methodsby A G SutcliffePresented by: Nestor RiveraEEL6883 UCF Spring 07IntroductionOOD more than OOP.Written in 1991.Object Oriented Development was not widely accepted.OutlineObject Oriented Concepts.Evaluation of Modeling Components. Evaluation Procedure.Object Oriented Methods.Review of Object Orientedness of Traditional Software Development Methods.Conclusions.Object Oriented ConceptsThree OOD principles that improve software design for reliability, maintainability, and reusability.Abstraction: Objects are an abstraction of part of the real-world. More maintainable and reusable.Encapsulation: Objects hide their internal contents from other components to improve maintainability. (information hiding)Inheritance: Organizing objects in class hierarchies to promote reuse. (subclass, superclass, hierarchical, multiple, polymorphism)Object Oriented Model of SystemsThe Object Oriented Model of Systems is composed of a network of objects communicating by messages.Each object specifies data and activity and may share properties according to a classification hierarchy.Evaluation of Modeling ComponentsObjects vs. Traditional Concepts of Entities and Functions.ISO TC97: entity, propositions and events.Entity: Any concrete or abstract thing of interest including association among things.Entities on three levels: Entity instance, entity type and entity class.Propositions, rules, constraints which specify the behavior of entities.Events: The fact that something has happened in either the universe of discourse, or the environment, or the information system.Evaluation of Modeling Components – Cont.Events are modeled as messages passed within a network of objects.Objects record state change resulting from events.Distinction between ISO TC97 and OOD: separation of data structure and rules, entities do not possess attributes, relationships are different.Object Orientation shares many of the ISO concepts but by no means all. Main divergence point: separation of activity and data specification.Evaluation of Modeling Components – Cont.Objects could be classified as data-oriented and task-oriented objects.Booch divides objects into actors (real-time systems), servers (data retrieval systems), and agents.Evaluation Procedure – Conceptual ModelingEvaluation framework: a meta-model of OO development. The data and processing control parts of a system are modeled in unit rather than separately.The method produces a network system model of objects communicating by messages.The method explicitly models object types and instances.Classification of objects is supported with property inheritance.Evaluation Procedure – Procedural GuidelinesThe method should guide the analyst towards identifying and describing objects.Guidance should be available for analysis, specification and design phases.Evaluation Procedure – Transformations and Products-Design transformations should support change of OO specifications into designs implementable in OOP languages.Evaluation Procedure – OO Meta-modelReview of Object Oriented and Traditional MethodsGoal: Highlight differences between OO and non OO methods.Case study: Video renting system for hotels. Snapshots of artifacts only.Object Oriented MethodsHierarchical Object Oriented Design (HOOD)Object Oriented System Design (OOSD)Object Oriented System Analysis (OOSA)Object Oriented Analysis (OOA)ObjectOryObject Oriented Methods – Hierarchical Object-Oriented Design (HOOD)Scores well on OO properties.Encourages modeling of objects explicitly.Objects are modeled in a hierarchical manner.Strong emphasis on the object interface specification and encapsulation.The OO model of systems is supported. Overall, incorporates many OO properties.Uses Booch’s concepts (actors and servers)Supports object classes, but inheritance and reuse are not made explicit.Real time-method -> data specification and associated inheritance receive less attention.Object Oriented Methods – Object-Oriented Systems Design (OOSD)Assumes analysis phase has been completed.Provides detailed notation for object classes and management of inheritance.Inter-object communications (event/message types)Detailed notation for interface description and encapsulation.No analysis advice is given.Object-Oriented Systems Design (OOSD) – Object Model Structure ChartObject Oriented Methods – Object-Oriented Systems Analysis (OOSA)Many heuristics for object identification and analysis, which help with initial abstraction and object modeling.Data modeling approach (ER modeling)Models an object relationship network with subclasses.State-transition specifications are constructed for each