Object Oriented System Analysis and Design (OOSAD)

1 OOSAD Module Page 1 Ambo University, Woliso Campus School of Technology and Informatics Department of Information Systems Object Oriented System Analysis and Design (OOSAD) COMPILED BY: HABTAMU KENO DEPARTMENT OF INFORMATION SYSTEMS 3, June, 2O WOLISO, ETHIOPIA OOSAD Module Page 2 Contents Chapter 1: Understanding the Basics: Object Oriented concepts .. 4 A Brief History .. 4 Object - Oriented Analysis .. 4 Object - Oriented Design .. 4 INTRODUCTION.

2 5 THE Object MODEL .. 5 Programming .. 5 Benefits of Object Model .. 10 3. Object - Oriented System .. 10 Object - Oriented PRINCIPLES .. 11 Analysis .. 13 Chapter Two: Object Orientation the new software paradigm .. 19 2. Structured vs. Object Orientation paradigm .. 19 The Potential Benefits of the Object Oriented paradigm .. 19 The Potential Drawbacks of OO .. 20 Object Standards .. 21 Chapter 3: Gathering user requirements .. 22 3. An Overview of Requirements Elicitation .. 22 Requirements elicitation includes the following activities.

3 22 Requirements Elicitation Concepts In this section, we describe the main requirements elicitation concepts used in this chapter. In particular, we describe .. 23 Functional Requirements .. 23 Nonfunctional Requirements .. 24 Fundamental requirements gathering techniques .. 25 Chapter 4: Ensuring Your Requirements are Correct: Requirement validation Techniques .. 26 4. Requirements Validation .. 26 The 6 Principles of Validation .. 26 Validation Techniques .. 27 Chapter 5: Determining What to Build: OO Analysis .

4 29 Overview of Analysis artefacts and their Relationships .. 29 The Unified Modeling Language (UML) .. 31 UML BASIC NOTATIONS .. 33 UML STRUCTURED DIAGRAMS .. 35 UML BEHAVIORAL DIAGRAMS .. 38 Chapter 6: Determining How to Build Your System : OO Design .. 42 System Design .. 42 Object - Oriented Decomposition .. 42 OOSAD Module Page 3 Identifying Concurrency .. 42 Identifying Patterns .. 43 Controlling Events .. 43 Handling Boundary Conditions .. 43 Object Design .. 43 Object Identification.

5 44 Object Representation .. 44 Classification of Operations .. 44 Algorithm Design .. 44 Packaging Classes .. 45 Design Optimization .. 46 IMPLEMENTATION STRATEGIES .. 47 Chapter seven : Software Testing .. 51 TESTING AND QUALITY ASSURANCE .. 51 Testing Object - Oriented Systems .. 51 Unit Testing .. 51 Subsystem Testing .. 51 Testing .. 51 Categories of System Testing .. 51 Object - Oriented Testing Techniques .. 51 Techniques for Subsystem Testing .. 52 The Full-Lifecycle Object - Oriented Testing (FLOOT).

6 52 Quality Assurance .. 53 Quality Assurance .. 54 Quality Factors .. 54 Chapter 8: Software Process .. 55 Process .. 55 Software Process .. 55 8. 3. Processes and Process Models .. 55 Component Software Processes .. 56 Approach for Process Specification .. 57 of Software Process .. 57 Software Development Process Models .. 59 Advantages of Prototyping .. 61 Limitations of Prototyping .. 61 Project Management Process .. 63 Process Management .. 66 The Unified Process .. 67 OOSAD Module Page 4 Chapter 1: Understanding the Basics: Object Oriented concepts A Brief History The Object - Oriented paradigm took its shape from the initial concept of a new programming approach, while the interest in Design and Analysis methods came much later.

7 The first Object Oriented language was Simula (Simulation of real systems) that was developed in 1960 by researchers at the Norwegian Computing Center. In 1970, Alan Kay and his research group at Xerox PARK created a personal computer named Dynabook and the first pure Object - Oriented programming language (OOPL)-Smalltalk, for programming the Dynabook. In the 1980s, Grady Booch published a paper titled Object Oriented Design that mainly presented a Design for the programming language, Ada.

8 In the ensuing editions, he extended his ideas to a complete Object Oriented Design method. In the 1990s, Coad incorporated behavioral ideas to Object - Oriented methods. The other significant innovations were Object Modelling Techniques (OMT) by James Rumbaugh and Object - Oriented Software Engineering (OOSE) by Ivar Jacobson. Object - Oriented Analysis Object Oriented Analysis (OOA) is the procedure of identifying software engineering requirements and developing software specifications in terms of a software System s Object model, which comprises of interacting objects.

9 The main difference between Object - Oriented Analysis and other forms of Analysis is that in Object - Oriented approach, requirements are organized around objects, which integrate both data and functions. They are modelled after real-world objects that the System interacts with. In traditional Analysis methodologies, the two aspects - functions and data - are considered separately. Grady Booch has defined OOA as, Object - Oriented Analysis is a method of Analysis that examines requirements from the perspective of the classes and objects found in the vocabulary of the problem domain.

10 The primary tasks in Object - Oriented Analysis (OOA) are: Identifying objects Organizing the objects by creating Object model diagram Defining the internals of the objects, or Object attributes Defining the behavior of the objects, , Object actions Describing how the objects interact The common models used in OOA are use cases and Object models. Object - Oriented Design Object Oriented Design (OOD) involves implementation of the conceptual model produced during Object - Oriented Analysis .