Part 2. Project Initiation

When developing use cases it is extremely important that the use case model’s place in the overall system development effort be well understood. When embarking on the system development effort, it can be tempting to jump in and start use case modeling right away. Although use cases were created to be applied in the early stages of system development, and although they are a very flexible technique, they are not the only technique that can be used to understand and model the system.

One of the greatest areas of both leverage and risk when developing a software system is in the initial scope of effort. This is where the overall concept of how the system will operate and support the business environment evolves. The objectives for a system are defined, key risks are discovered, and the overall direction of the system development is set. Before modeling how individual actors will interact with the system, it is critical to understand what business problem the system is addressing and its overall size and boundaries.

Second, placing the use case model within the context of the overall development effort is important in understanding and analyzing the system’s requirements and behaviors and the role of the use case. Developers need to understand the other techniques that will be used to “balance” the complete system picture and how the techniques can be drawn on to fill in the picture.

Because we feel it is so important for the use case modeler to be alert to these issues, this part presents two short chapters on scoping the system and balancing the use case model.