Beyond Code

Changing Requirements

Requirements change. This observation is so common among practitioners that it is now generally taken as an undisputed fact of life, like death and taxes. However, is it really true, and if yes, to what extent?

At least three questions beg asking:

1. What is the quality of the baseline that change is measured against? How much care and know-how went into the original set or requirements? There is a real danger of creating self-fulfilling prophecies: Since requirements are expected to change, little effort is made to determine them ahead of time. No wonder that they change...
2. Are the changes predictable? A careful analysis of the original situation will most likely determine a number of areas where change is likely. A good design can take this into consideration, so that change, when it comes, is already accomodated for in the architecture. This does not mean that everything should be considered subject to change! If the business sponsors really can't provide a fair degree of stability in the features they want to see in the system under construction, then they should invest more effort into establishing their business case. It is an error to run commercial software development as either research and development, and it is the responsibility of the technical staff to point this out.
3. To what degree is change invited? Does the technical team take a firm position to the requirements that were originally negotiated or does it give the impression that the customer just has to ask? Requirements typically originate with the business domain experts. Domain experts come from a business background, and may have a habit of trying to maximize their "gain" in any situation they find themselves in. Software developers on the other hand often are quiet, accomodating people, who may not have the social sophistication to deal effectively with a shrewd business person's bullying tactics. Please note that I am not suggesting either party acts out of malicious intent - just old habits playing themselves out, probably subconsciously.