By Henry Cheung
A SPECIFICATION, according to the Oxford Encyclopaedic English Dictionary, is "a detailed description of the construction, workmanship, materials, etc., of work done or to be done, prepared by an architect, engineer, etc.". In other words, it is a translation of the solution to a particular problem formulated in the mind of the originator. Note that I have used the word "translation" as in most circumstances, the expression of ideas into written form is quite often very "lossy" - the specification does not always reflect the complete requirements. This is often amplified by the impreciseness and ambiguity of the English language, which is the most frequently used language in specifications, leading to a different interpretation of what is actually required.In the modern engineering world, there are broadly two major types of engineering design: the engineer's design, and the contractor's design. These two modes of engineering would lead to vastly different specifications. Although the engineer's systems may seem to be easier to implement, as all the design decisions have already been made and the appropriate solution incorporated in the specification. All the contractor needs to do is to follow the instructions, and at a certain point in time, the system is produced! Not exactly. We have seen in many occasions this is not the case.
So you may ask, what is the flaw in this model? Both the designer and the implementer are to be blamed. The designer may have taken certain assumptions in his design, but he may have ignored some other very important factors as well. These will, according to Mr. Murphy in his famous Murphy's Law, will definitely cause problems somewhere along the development. The implementer may have interpreted the design and deviates from the original intentions of the designer.
Does the contractor's design faire better? Yes and no. The engineer in writing the specification needs to cater for the various design options, and have to safeguard the key requirements are properly defined. This has to be done in conjunction with the consideration of not putting any particular design on paper, to allow for a fair open tender. The result is most often generalisation of specifics and the contractor will interpret to his favour.
No win situation! Indeed we have seen in major projects that there would be a lot of chaos at the commissioning of the systems. If we analyse the cause, it does reveal the most fundamental problem: communication. It is very difficult to communicate a concept or a particular model in one's mind to reality, passing it through a number of intermediates, with various degree of distortion and adjustments.
Indeed writing specification is a black art!