Clarifying how customers interact with products and systems is essential for requirement collection and high-level communication with stakeholders. A use case model diagram visualizes a product's users, how they interact with it, and what it does. However, what exactly is a use case? Moreover, why is it an essential tool for project managers? While the software development environment is often used to disassemble complex ideas, use cases in project management can play an equally important role in gathering requirements and establishing project scope.
A use case describes how people who use the process or system achieve their goals. It is generally related to a software system, but can be used for any process. For example, suppose a chef has a goal of making a cheese sandwich. It describes how a chef prepares that sandwich through a series of documented steps. Use cases help project managers understand where errors might occur in their process and design features to resolve them.
Project managers must have a sound knowledge of use cases because it bridges the gap between business justification and technical requirements and helps share strategy with stakeholders. Use cases provide a structure for setting up the scope of a project and gathering customer requests. For example, a project manager at an educational technology company has come up with the latest product idea for his company: an app for students who can take a live class for a monthly fee. By creating it for this application, stakeholders, and project teams can learn who the customer is, how the customer contacts the product, and the project scope gaps and requirements.
The use case can be as basic or detailed as needed, depending on the system to be discussed and the intended audience. Its documentation requires that the project manager establish and identify several essential components.
System: A system is a product, service, or software discussed.
Actor: An actor is something else that shows behavior when interacting with a user or system. There are four types of actors: the system being discussed, the internal actor, the primary actor, and the secondary actor. The latter two systems are most often mentioned. The primary actor may initiate an interaction with the system, while the secondary actor may provide services to the system.
Use case: It outlines the possible success and failure scenarios when actors interact with the system. This section establishes the primary success scenario, the most desirable result between the actor and the system. It also establishes an alternate path that explains what happens in the case of failure or error.
The use case has added value because it helps explain how the system should work and brainstorm what does not work. It provides a list of goals used to demonstrate the complexity and expenditure of the system. The project team can negotiate which features are required and built.