Software engineering (SE) is the design, development, and documentation of software by applying technologies and practices from computer science, project management, engineering, application domains, interface design, digital asset management and other fields.The term software engineering was popularized after 1968, during the 1968 NATO Software Engineering Conference (held in Garmisch, Germany) by its chairman F.L. Bauer, and has been in widespread use since.
The term software engineering has been commonly used with a variety of distinct meanings:
As the informal contemporary term for the broad range of activities that was formerly called programming and systems analysis;
As the broad term for all aspects of the practice of computer programming, as opposed to the theory of computer programming, which is called computer science;
As the term embodying the advocacy of a specific approach to computer programming, one that urges that it be treated as an engineering discipline rather than an art or a craft, and advocates the codification of recommended practices in the form of software engineering methodologies.Software engineering is "(1) the application of a systematic, disciplined, quantifiable approach to the development, operation, and maintenance of software, that is, the application of engineering to software," and "(2) the study of approaches as in (1)." – IEEE Standard 610.12
Scope and focus
Software engineering is concerned with the conception, development and verification of a software system. This discipline deals with identifying, defining, realizing and verifying the required characteristics of the resultant software. These software characteristics may include: functionality, reliability, maintainability, availability, testability, ease-of-use, portability, and other attributes. Software engineering addresses these characteristics by preparing design and technical specifications that, if implemented properly, will result in software that can be verified to meet these requirements.Software engineering is also concerned with the characteristics of the software development process. In this regard, it deals with characteristics such as cost of development, duration of development, and risks in development of software.
The need for software engineering
Software is often found in products and situations where very high reliability is expected, even under demanding conditions, such as monitoring and controlling nuclear power plants, or keeping a modern airliner aloft Such applications contain millions of lines of code, making them comparable in complexity to the most complex modern machines. For example, a modern airliner has several million physical parts (and the space shuttle about ten million parts), while the software for such an airliner can run to 4 million lines of code.Software engineering resembles many different fields in many different ways. The following paragraphs make some simple comparisons.
Mathematics
Programs have many mathematical properties. For example the correctness and complexity of many algorithms are mathematical concepts that can be rigorously proven. Programs are finite, so in principle, developers could know many things about a program in a rigorous mathematical way. The use of mathematics within software engineering is often called formal methods. However, computability theory shows that not everything useful about a program can be proven. Mathematics works best for small pieces of code and has difficulty scaling up.
Engineering
Software Engineering is considered by many to be an engineering discipline because there are pragmatic approaches and expected characteristics of engineers. Proper analysis, documentation, and commented code are signs of an engineer. David Parnas has argued that software engineering is engineering. Programs have many properties that can be measured. For example, the performance and scalability of programs under various workloads can be measured. The effectiveness of caches, bigger processors, faster networks, newer databases are engineering issues. Mathematical equations can sometimes be deduced from the measurements. Mathematical approaches work best for system-wide analysis, but often are meaningless when comparing different small fragments of code.
Manufacturing
Programs are built in as a sequence of steps. By properly defining and carrying out those steps, much like a manufacturing assembly line, advocates hope to improve the productivity of developers and the quality of final programs. This approach inspires the many different processes and methodologies. While others, such as the authors of the Programmer's Stone, contend this view "[is] in fact claiming to be able to implement an Artificial Intelligence that simulates a production line designer".
Project management
Commercial (and many non-commercial) software projects require management. There are budgets and schedules to set. People to hire and lead. Resources (office space, computers) to acquire. All of this fits more appropriately within the purview of management.
from : en.wikipedia.org
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