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Methodology Review. Chapter 7 Part 2: Design Methodology Object-Oriented Modeling and Design Byung-Hyun Ha bhha@pusan.ac.kr. Lecture Outline. Introduction OMT as S/W Engineering Methodology OMT Methodology Impact of an Object-Oriented Approach. Introduction.
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Methodology Review Chapter 7 Part 2: Design Methodology Object-Oriented Modeling and Design Byung-Hyun Ha bhha@pusan.ac.kr
Lecture Outline • Introduction • OMT as S/W Engineering Methodology • OMT Methodology • Impact of an Object-Oriented Approach
Introduction • In Part 1, modeling concepts • OMT concepts, for object, dynamic, and functional models • What constitutes a model • In Part 2, design methodology • Process for devising the three OMT models • How to formulation a model • Language-independent methodology, applied equally well to object-oriented languages, traditional procedural language, and databases • In Part 3, implementation • How this generic design maps to specific implementation targets
OMT as S/W Engineering Methodology • Software engineering methodology • A process for the organized production of software, using a collection of predefined techniques and notational conventions • Presented as a series of steps with techniques (presented in Part 1) associated with each step • The steps are usually organized into a lifecycle consisting of several phases of development • Span of complete software lifecycle • Initial formulation of the problem • Analysis of requirement, design, implementation, and testing of the software • Operational phase during which maintenance and enhancement are performed
OMT as S/W Engineering Methodology • Two approaches to software development • Rapid prototyping approaching • A small portion of the software is initially developed and evaluated through use • The software is gradually made robust through incremental improvement to the specification, design, and implementation • Lifecycle approach • Software is fully specified, fully designed, then fully implemented OMT methodology applies equally well in either case
OMT Methodology • Phases • Analysis, system design, and object design • Analysis phase • Concerned with understanding and modeling the application and the domain within which it operates • Initial input: a problem statement which describes the problem to be solved and provides a conceptual overview of the proposed system • Output: a formal model that captures the three essential aspects of the system
OMT Methodology (cont’) • System design phase • Overall architecture of the system is determined • The system is organized into subsystems • Priorities are established for making design tradeoffs • Object design phase • The analysis model are elaborated, refined and then optimized to produce a practical design • There is a shift in emphasis from application concepts toward computer concepts • Determining efficient algorithms, optimized structure of object model, etc.
Impact of an Object-Oriented Approach • Shifting of development effort into analysis • Resulting design is cleaner and more adaptable • Future changes are much easier • Emphasis on data structure before function • A more stable bases are given to development process • Seamless development process • Refining the model developed in analysis phase progressively during throughout the development cycle • Interactive rather than sequential • Less chance of introducing inconsistencies and errors