Need for the subject

What is software engineering? Phases? What will you do in requirement gathering? What is requirement elicitation? Analysis? Design? How you can convert requirements into design form?

What can be the input for the developer? What are the things need to be known by the developer to start with any project? What are the roles of developer/client/manager/end user/designer/analyser? What should do if final project in the production need any change?

What are the requirements of an efficient product? What is maintenance phase? How we can carry out the changes? What are the phases need to be touched upon if we are carrying out modification of product? How we can minimize modification after delivering the product?

What are the basic expectations of any good product if we want to win the market? What are the expectations of any client? Is clients technically sound? How we can reduce the time /cost of maintenance?

UNIT-I

Introduction Software development is dynamic and always undergoes major changes. Methods used will differ significantly. Vast number of tools & methodologies are available for system development.

Systems Development Refers to all activities that go into producing an information systems solution. Activities : Analysis Modeling Design Implementation Testing and Maintenance

Software Development Methodology Is a series of process that, if followed, can lead to the development of an application. The software processes describe how the work is to be carried out to achieve the original goal based on the system requirements. Each process consists of a number of steps and rules to be performed during development. Software development process continues to exist as long as the development system is in use/operation.

Two Orthogonal Views of the Software Object-oriented Systems Development methodologies view software as a collection of programs (functions) and isolated data. Also called Procedure/Function Oriented Methods. Algorithms + Data Structures = Programs; “A software is a set of mechanisms for performing certain action on certain data”. The traditional approach focuses on the functions of the system(what is it doing?) But object-oriented systems development focuses on object which combines data and functionality.

Object-Oriented Systems Development Methodology Focuses on the objects, which combines data and functionality. Characteristics: Emphasis is on data rather than procedure. It’s the way to develop software by building modules that can be replaced, modified and reused. Objects are identified in programs. Each object has attributes and methods and objects are grouped into classes. Functions that operate on the data of an object are tied within the object itself. Data is hidden and cannot be accessed by external functions. Objects communicate through functions. Addition of new functions and data can be carried out easily.

Why an Object Orientation? Object-oriented methods enable us to create sets of objects that work together to produce better software. It enable us to produce systems that are easier to adapt to changing requirements, easier to maintain, more robust and promote greater design and code reuse. Reasons: Higher level of abstraction So object-oriented approach supports abstract at object level as the objects encapsulates both data and functions.

2. Seamless transition among different phases of software development The traditional software development requires different methods for each steps. The transition between different modules is difficult and slows down the development process. Also increases the code size and errors. but object-oriented approach uses same language in all levels. So it reduces the level of complexity and redundancy.

3. Encouragement of good programming technique using object-oriented languages is recommended to achieve benefits of object orientation. This makes easier to produce more modular and reusable code by using class and inheritance concepts.

4. Promotion of reusability: Classes are designed generically with reuse as a constant background. Also inheritance allows classes to be built from each other and only differences and enhancements between the classes is designed and coded. The remaining can be reused without any change.

Overview of Unified Approach The Unified Approach (UA) is a methodology for software development. The UA, based on methodologies by Booch, Rumbaugh, & Jacobson, tries to combine the best practices, processes and guidelines along with the Object Management Group's Unified Modeling Language. The Unified Modeling Language (UML) A set of notations and conventions used to describe and model an application. The UML does not specify a methodology or whatsteps to follow to develop an application; that would be the task of UA.