Introduction to Software Engineering

The field of software engineering is related to the development of software. Large software needs systematic development unlike simple programs which can be developed in isolation and there may not be any systematic approach being followed. In the last few decades, the computer industry has undergone revolutionary changes in hardware. That is, processor technology, memory technology, and integration of devices have changed very rapidly. As the software is required to maintain compatibility with hardware, the complexity of software also has changed much in the recent past. In 1970s, the programs were small, simple and executed on a simple uniprocessor system. The development of software for such systems was much easier. In the present situation, high speed multiprocessor systems are available and the software is required to be developed for the whole organization. Naturally, the complexity of software has increased many folds. Thus, the need for the application of engineering techniques in their development is realized. The applications of engineering approach to software development lead to the evolution of the area of Software Engineering. The IEEE glossary of software engineering terminology defines the Software Engineering as:

(a) The application of a systematic, disciplined, quantifiable approach to the development, operation and maintenance of software, that is, the application of engineering to software. (b) The study of approaches in (a).

There is a difference between programming and Software Engineering. Software Engineering includes activities like cost estimation, time estimation, designing, coding, documentation, maintenance, quality assurance, testing of software etc. whereas programming includes only the coding part. Thus, it can be said that programming activity is only a subset of software development activities. The above mentioned features are essential features of software. Besides these essential features, additional features like reliability, future expansion, software reuse etc. are also considered. Reliability is of utmost importance in real time systems like flight control, medical applications etc.