Behavioral UML Diagrams In Business Analysis

According to a well-known proverb, a picture is worth a thousand words. This indicates that complex concepts can be represented with simple visual elements. In today’s society, it is essential and beneficial for a business analyst to visualize their work. Throughout a project, a BA collaborates with variety of individuals, including end users and developers. In this cooperation and communication, the simpler and clearer we express the processes, functions and flows we work on, the easier the shared understanding among all stakeholders will be. I’d like to provide some general information about UML diagrams and then describe in detail how some behavioral UML diagrams can be used in business analysis and which one is useful at which step.

What Is UML ?

UML (Unified Modeling Language) is a common modeling language that makes possible to understand a system by anyone who wants.

It was created by Grady Booch, Ivar Jacobson, and James Rumbaugh (known as 3 amigos) in 1990s. Their first goal in creating it was reducing the complexity.

Although it was developed for complex software systems, it is not just for software developers. It can also be used by business analysts to visualize the requirements and work that needs to be done to meet the need.

Today according to the last UML version there are basically two types of UML diagrams. These are structural and behavioral diagrams. Each of them has also sub categories.

Structural UML diagrams basically shows the static view and elements of a system like classes, objects. These kind of diagrams are commonly used in software architecture documentations.

Behavioral UML diagrams shows the dynamic view of a system and describes the functioning it.

For a business analyst behavioral UML diagrams helps them in various ways. A BA can visualize both the current state or the targeted state by using these diagrams. It also helps them collaborate during design as it is simple and understandable.

Let’s go into more detail about three behavioral UML diagrams from a business analyst perspective.

Use Case Diagram

A use case diagram shows the interactions between the user and the system. You can visualize the user actions and the systems responses by drawing a use case diagram. It has steps of a success case that the user takes to perform a function. As it is, it can be very useful in understanding what customer, end users need in first place. It also an easy to understand diagram by everyone. Due to all these benefits use case diagrams are good choices for requirement gathering or determining scope.

There are four component for use cases.

Actors: Someone interacts with the system.

Use Case: System function.

Relationship: Lines that show the interactions between an actor and a use case.

System Boundary: A rectangle shape shows the limit of the system with use cases.

Activity Diagram

You can illustrate the flow of the actions in a system with activity diagram in a sequential manner and it is very useful for modeling business process. You can also create and activity diagram for a selected use case show entire flow related to that case and you can model some software architecture elements like functions or methods.

An activity diagram can be used to show a more clear view of a business requirements in a technical way. Therefore it can be used in the functional specification documents. For a BA, activity diagram can be used to communicate with both customer and developers because it is an easy to understand diagram, although sometimes complex.

Activity diagram consists of these most common components.

Start node: A black circle represent the begining of the activity.

Action: A round-edged rectangular shows the actions in the activity.

Control flow: Connectors show the flow between actions.

Decision node: A diamond shape represent a decision point with alternate paths.

End node: An outlined black circle represents the ending of the activity.

We can draw a basic activity diagram as a sample for the “make payment” use case above.

Sequence Diagram

A sequence diagram is a message-based diagram shows how and in what order processes or objects interact during a scenario. Unlike the activity diagrams, it describes the interactions between objects not the activities.

A BA can use this diagram if a time ordered flow of a process is needed or beneficial. It can be used to show the behavior of the objects in more detail in a use case. It can also make the use case more understandable and clear for coding phase by developers. It may be a proper choice for the systems that has multiple web services or layers.

A sequence diagram basically consists of these components.

Object: A rectangle shows an object or a class in the diagram

Lifeline: A dashed vertical line depicts an individual participant in a sequence diagram.

Message: A solid line arrow shows the message flows between two activities.

Reply message: A dashed arrow shows the return message to the caller.

Activation box: It represents the time that the entity performs a task.

Conclusion

Using the visual elements make you collaborate more easily and make your analysis more understandable. UML diagrams has many diagram options that you can choose depend on your work and it is a good idea to try to use it as much as you can.