- Some definitions of Software Engineering
- What is Software Engineering?
- What is it different from other forms of engineering?
- Importance of software engineering
- Essential attributes of good software
- Some Questions
Some definitions of Software Engineering
The establishment and use of sound engineering principles (methods) in order to obtain economically viable software that is reliable and works on real machines.
(Bauer, F. L. Software Engineering. Information Processing 71., 1972)
The application of a systematic, disciplined, quantifiable approach to the development, operation, and maintenance of software; that is, the application of engineering to software.
(IEEE Std 610-1990).
Software engineering is the technological and managerial discipline concerned with systematic production and maintenance of software products that are developed and modified on time and within cost estimates.
(Fairley, R. Software Engineering Concepts. New York: McGraw-Hill, 1985)
SEI software engineering definition from 1990 SEI Report on Undergraduate Software Engineering Education (CMU/SEI-90-TR-003 ):
- Engineering is the systematic application of scientific knowledge in creating and building cost-effective solutions to practical problems in the service of mankind.
- Software engineering is that form of engineering that applies the principles of computer science and mathematics to achieving cost-effective solutions to software problems.
Software engineering is the discipline concerned with developing large applications. Software engineering covers not only the technical aspects of building software systems, but also management issues, such as directing programming teams, scheduling, and budgeting.
What is Software Engineering?
- Engineering deals with the understanding, design and implementation of large, complex systems.
- Software engineering is concerned with theories, methods and tools for professional software development.
- It’s not an exact science, rather a collection of ideas, techniques and tools which assist in the software development process.
Software engineer is the disciplined process of producing software:
- It helps communicates the design to members of the team
- It helps manage the process through the life cycle: from concept to delivery and through to decommissioning
What is it different from other forms of engineering?
Many of the techniques of general product management are applicable to the software domain. However, there are certain characteristics that distinguish them from others. These are:
- Invisibility: when a physical artefact is being manufactured or constructed the progress can actually be seen. However, with software, progress is not always immediately visible.
- Complexity: as a general statement, software products are more complex than other engineering artefacts.
- Flexibility: A major advantage of software is the ease with which it can be changed. Therefore, the general perception is that it is easier to accommodate changes in software than to change the physical or organisational systems in which the software interfaces with.
- Hence, software systems are likely to be subject to a high degree of change.
Importance of software engineering
- More and more, individuals and society rely on advanced software systems. We need to be able to produce reliable and trustworthy systems economically and quickly.
- The economies of ALL developed nations are dependent on software.
- More and more systems are software controlled
- Software engineering is concerned with theories, methods and tools for professional software development.
- Expenditure on software represents a significant fraction of GNP in all developed countries.
Essential attributes of good software
| Product characteristic | Description |
|---|---|
| Maintainability | Software should be written in such a way so that it can evolve to meet the changing needs of customers. This is a critical attribute because software change is an inevitable requirement of a changing business environment. |
| Dependability and security | Software dependability includes a range of characteristics including reliability, security and safety. Dependable software should not cause physical or economic damage in the event of system failure. Malicious users should not be able to access or damage the system. |
| Efficiency | Software should not make wasteful use of system resources such as memory and processor cycles. Efficiency therefore includes responsiveness, processing time, memory utilisation, etc. |
| Acceptability | Software must be acceptable to the type of users for which it is designed. This means that it must be understandable, usable and compatible with other systems that they use. |
Some Questions
- What is software?
- Computer programs and associated documentation. Software products may be developed for a particular customer or may be developed for a general market.
- What are the attributes of good software?
- Good software should deliver the required functionality and performance to the user and should be maintainable, dependable and usable.
- What is software engineering?
- Software engineering is an engineering discipline that is concerned with all aspects of software production.
- What are the fundamental software engineering activities?
- Software specification, software development, software validation and software evolution.
- What is the difference between software engineering and computer science?
- Computer science focuses on theory and fundamentals; software engineering is concerned with the practicalities of developing and delivering useful software. In addition, software engineering is generally considered to be a subset of computer science.
- What is the difference between software engineering and system engineering?
- System engineering is concerned with all aspects of computer-based systems development including hardware, software and process engineering. Software engineering is part of this more general process.
- What are the key challenges facing software engineering?
- Coping with increasing Complexity, demands for reduced delivery times and developing trustworthy software.
- What are the costs of software engineering?
- Roughly 60% of software costs are development costs, 40% are testing costs. For custom software, evolution costs often exceed development costs.
- What are the best software engineering techniques and methods?
- While all software projects have to be professionally managed and developed, different techniques are appropriate for different types of system. For example, games should always be developed using a series of prototypes whereas safety critical control systems require a complete and analyzable specification to be developed.
- What differences has the web made to software engineering?
- The web has led to the availability of software services and the possibility of developing highly distributed service-based systems. Web-based systems development has led to important advances in programming languages and software reuse.
