هندسة برامجيات نظري1

The people can’t turn the modern world without software. National infrastructures and utilities are controlled by computer-based systems and most electrical products include a computer and controlling software. Industrial manufacturing and distribution is completely computerized, as is the financial system. Entertainment, including the music industry, computer games, and film and television, is software intensive. Therefore, software engineering is essential for the functioning of national and international societies.
Software systems are theorized and governed by physical laws, or by manufacturing processes. The lack of physical constraints, software systems can quickly become extremely complex, difficult to understand, and expensive to change.
There are many different types of software systems, from simple embedded systems to complex, worldwide information systems. It is pointless to look for universal notations, methods, or techniques for software engineering because different types of software require different approaches for software engineering.
There are still many reports of software projects going wrong and ‘software failures’. Software failures are a consequence of two factors:
1. Increasing demands: Systems have to be built and delivered more quickly; larger, even more complex systems are required; systems must to have new capabilities that were previously thought to be impossible. Existing software engineering methods cannot cope (manage in spite of difficulty) and new software engineering techniques must to be developed to meet new these new demands.
2. Low expectations: Many companies have adopted software development as their products and services have evolved. They do not use software