Adaptive Processes Introduction to Software Engineering Adaptive Processes

Simpler, Faster, Better 2 Objectives To introduce software engineering and to explain its importance To set out the answers to key questions about software engineering To introduce ethical and professional issues and to explain why they are of concern to software engineers

Adaptive Processes Simpler, Faster, Better 3 The economies of ALL developed nations are dependent on software More and more systems are software controlled Software engineering expenditure represents a significant fraction of GNP in all developed countries Almost all devices that we use today have something to do with software All other tools helped man – this one helps the most important organ – the brain Importance Of Software

Adaptive Processes Simpler, Faster, Better 4 What Is Software? Software: Programs that you use to make a computer do different things ( Cambridge Learners Dictionary) Instructions (Computer Programs) that when executed provide desired function and performance Data structures that enable the programs to adequately manipulate information and Documents that describe the operation and use of program ( Software Engineering by Pressman )

Adaptive Processes What Is Engineering?

Adaptive Processes Simpler, Faster, Better 6 Software engineering is the application of a systematic, disciplined, quantifiable approach to the development, operation and maintenance of software, i.e. the application of engineering to software ( IEEE ) Software engineering is the establishment and use of sound engineering principles in order to obtain economically software that is reliable and works efficiently on real machines ( Software Engineering by Pressman ) Software Engineering

Adaptive Processes Simpler, Faster, Better 7 Characteristics of Softwares SW is developed or engineered, it is not manufactured in classical sense Software does not wear out Most SW is custom built, rather than being assembled from existing components Typically errors are high when software is built or changed and the error rates comes down The cost of correction / change increases exponentially when we move ahead in the life cycle of a SW project

Adaptive Processes Simpler, Faster, Better 8 Cost of Correction Cost Project Phase

Adaptive Processes Simpler, Faster, Better 9 Software costs often dominate system costs. The costs of software on a PC are often greater than the hardware cost Software costs more to maintain than it does to develop. For systems with a long life, maintenance costs may be several times development costs Software engineering is concerned with cost-effective software development Software Costs