IT Success!: Towards a New Model for Information Technology

3.1. The unintended consequences of the waterfall method

Under the traditional model, the IT department develops systems for the business through a standard client-vendor relationship based on a contractually signed-off requirements specifications document. This then drives a sequential waterfall method, which is a strict linear approach from analysis, design, development and testing through to implementation, with each phase performed by different teams of specialists (see Figure 2.1 in the previous chapter).

Just as for our pizza parlour processes (see Figure 2.3 in the previous chapter), the 'it's not my problem' problem applies. This means that as far as the analyst is concerned, the user knows what he wants; as far as the developer is concerned, the analyst drafted the correct specifications; and so on all the way down the line. In other words, it is possible to produce something to spec which doesn't correspond to what the customer really wanted. Paradoxically, it is also possible to produce something to spec which actually does correspond to what the customer asked for, but which did not yield the desired business results, e.g. because of an unrealistic business case.

In either case, IT would defend its own narrow position by saying 'it's not my problem' since that's what the customer asked for. It would not do so out of any disregard for the customer's real needs, but simply because it is working to the rules of a particular business model.

Just how perverse such rules ...