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Software engineering (SE) is a term indicating the profession

concerned with the creation and maintenance of software by the use

of relevant computer science (CS), project management, and other

technologies and practices.

Software engineering attempts to bring the lessons learned fromengineering disciplines (E.g. mechanical, electrical, chemical etc.) to

bear on the software development process.

In the past many software projects have failed due to poor standards,

bad programming and inadequate project management practices. SE

techniques can improve the quality of the finished software product as

well as the productivity and quality of program developers. It has beenestimated that there are in excess of 2 million persons worldwide that

can be considered to be involved in various SE efforts.

Software Engineering vs. Computer Science

Unlike computer science which deals with the underlying theory of

programs, SE is concerned with the approaches taken to computer programming, insisting that it be treated in a highly structured manner

similar to a mainstream engineering profession rather than as an art or

a craft. Diverse views exist in the SE community as to the extent to

which the development of software mirrors a typical engineering

process. Nevertheless there have been several successful SE projects

including the popular Linux OS software, space shuttle software and

banking software.

Qualifications for Software Engineers

Upward of 50% of software engineers have earned a computer

science degree. There is also a trend towards the earning of

specialized undergraduate and graduate degrees in the field of





software engineering (as opposed to CS). In addition persons often

specialize in other fields such as computer engineering, medical

informatics or biology as some systems require highly specialized and

detailed knowledge outside of traditional CS or mathematics areas.

E.g. DNA computer system may require detailed knowledge from the

fields of biology or medicine.

Waterfall Model

A major aim of SE is to bring order out of the seemingly chaotic task

of writing computer programs. To achieve this end a commonly cited

approach is the use of the so-called waterfall model. Under this model

progress is made by systematically proceeding from one phase of development to another. Imagine water cascading down a series of

waterfalls along a river.

Basic Waterfall Stages –

Step 1 – Analysis: The problem(s) thoroughly investigated and

definedStep 2 – Specification: the problem written out in a clear and

precise manner; a list of all the things required produced

Step 3 – Design: A particular approach decided upon and a

detailed plan of that plan produced

Step 4 – Implementation: The plan put into action as design turned

into program code (coding)

Step 5 – Testing : The code produced in the implementationsection scrutinized by conducting series of tests

Step 6 – Maintenance: The project is finished but there is

acknowledgement that changes will have to be made throughout

the lifetime of the software

Typically the first five steps are short-term (i.e. may last a few days,





weeks, months or years). The last step (Maintenance) is long term

(several years).

Other Models

The waterfall model is far from ideal as persons often lack theexperience to adequately finish one stage of the process before

continuing to the next. It must be noted that oftentimes errors which

are produced at one stage are not discovered until later stages, a

situation which is difficult and expensive to correct. Other models

such as the evolutionary models have been developed which are

more complex but allow greater flexibility.

SE Debates

Due to the diverse fields which encompass SE such as computer

science, engineering and mathematics, vigorous debates have

occurred over the years as to the essential characteristics of SE.

SE has characteristics belonging to maths, science, engineering andeven art.

Mathematical properties: - It is clear that all programs have properties

that can be mathematically handled because they are produced from

algorithms which themselves have mathematical properties. Some

have argued that SE is another branch of mathematics.

Scientific properties: - Science is characterized by the ability to

theorize, experiment and measure. Programs have properties that can

be measured and subjected to scientific approaches.

Artistic properties: - The fact that software must be pleasing to those

who use it means that some degree of art must be applied to maximize





the utility of the software. Defining programming as an art would

suggest that no formal rules or strategies are sufficient to develop

software but that it must involve individual subjective tastes.

The role of Project Management: - There is also the fact that large

programs are built by teams of persons working on successive projects. The project management requirements of such an effort, as

well as the strict engineering discipline approach, become more

important as the size of the software product (i.e. various related

programs) increases.

The debates will continue well into the future as software developers

continue to require multiple approaches from the diverse fieldsmentioned such as mathematics, science and art.

cape computer science unit 2 - livebinde

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