LETTER: Engineering a piece of software

From Mr Peter Bye

Sir: Hamish McRae asks ("Is this the start of something good?", 3 August) the meaning of capacity in a service company. As an example, he states that "it does not take long to write more software". This rather indicates a lack of knowledge about software production.

Although frequently classed as a service industry, software is really a branch of engineering. Any major application, or piece of systems software, has to be specified, designed, written, tested, piloted and finally deployed. This can take hundreds of man years in the case of very large systems.

Once it is produced, it can be copied for trivial costs, but copying is not the same as production. Apart from the reproduction costs, software therefore has a lot in common with any other engineering activity.

Sophisticated service industries, such as banks and airlines, depend heavily on information technology for product delivery. Lack of capacity to produce and deploy suitable software can delay or otherwise compromise the introduction of new products. A glance at the many examples of projects that have failed because of the inability to deliver the necessary software should indicate to anyone that it does indeed take time to write more software!

Yours sincerely,

Peter Bye

London, N1