Data Driven Decisions

Chapter 21Originating Requirements

Originating requirements are an evolution of use cases. They describe what a system should do on a factual and definitive basis, such that it is a requirement that the system performed the desired function. Otherwise, the system would be determined in a failure state. The most important technical component of requirements is that they use specific verbs, and those verbs most commonly are will or shall (Figure 21.1). A computer shall weigh ten pounds. An operator will log in at 8 am New York City time. These are requirements. They must happen in order for the system to function. This is different from use cases where – juxtaposed to a use case – the originating requirement is more definitive, and the use case is more fluid. The comparative use case in the two examples of requirements I just gave you would be considered something like “the operator will arrive at work in the morning.”

Figure 21.1

Originating requirements describe a system and how it functions. They are the backbone of many systems engineering processes, and they identify how the product is expected to work down to a very specific level.

Originating requirements are not a marketing or sales statement. The best way to describe their purpose is to consider how they would be presented to a project manager. Imagine if, at any point, a project was handed off to a contractor or ...