Use case and activity diagram

Business Analysts use UML (Unified Modeling Language) to interpret the business case to the technical team as well as other stakeholders in a simple but elaborate language.

Here, we are going to discuss two of the more popular UML diagrams used by business analysts – Use Case diagram and Activity diagram.

Use Case diagram is a high level diagram which gives an overview of the solution to the business case at hand. It is a user perspective diagram explaining the solution and business case with respect to the users, who are referred to as actors. Now, we have two types of actors – Primary and Secondary. Primary actor is one who initiates the process and secondary actors basically perform support function. Let us take the example of a movie; the main actor plays the lead in the movie, having maximum lines and much more time in the limelight, while the supporting actors come in and out of the movie at various stages, depending on the narrative. In this case, the actor playing the lead is the primary actor while the supporting cast comprises of secondary actors. Similarly, in a business case, the Primary actor is one who initiates the process and is also involved in most of the essential use cases.

Activity diagram, like the name suggests, explains the activities or flow of actions involved in the process. It is a system perspective diagram, where the activities involved in the IT solution to the business case is explained in a more elaborate way. Functional and technical requirements are explained in this diagram. It is a very detailed diagram explaining all the activities from start to end in a sequential manner. We are able to explain conditions here and also we can provide the basic flow as well as the alternate flow in this diagram.