Activity Diagrams – Advantages, Disadvantages and Use Applications

Activity diagrams describe the actual behavior of the workflow of a system in information technology. These diagrams are very similar to state diagrams because activities are the actual state of doing something. These diagrams describe the real state of the activities of a system showing the entire sequence of activities carried out. Also, these diagrams can show activities that are conditional or parallel.

When to use: activity diagrams

Activity diagrams should be used in conjunction with other modeling techniques, such as interaction diagrams and state diagrams. The main reason behind the use of these diagrams is to model the workflow behind the system being designed. These diagrams are also useful for analyzing a use case by describing what actions should be performed and when they should occur, describing a complicated sequential algorithm, and modeling applications with parallel processes.

Advantages of activity diagrams:

• The UML modeling language included that these diagrams are usually easily understandable by both analysts and interested parties.
• In UML for the IT Business Analyst, “The activity diagram is the most useful for the IT BA to represent the workflow [because] It’s easy to understand, both for BAs and end users.”
• Since they are among the easiest to use diagrams available, they are generally considered an essential tool in an analyst’s repertoire.
• Additionally, as noted above, activity diagrams allow an analyst to display multiple conditions and actors within a workflow through the use of lanes. However, the rails are optional as a single condition or the actor is usually shown without them.

Disadvantages of activity diagrams:

The UML modeling language understands that these diagrams have the potential to become too complex because their easy-to-use nature can lend itself to exhaustive description. In other words, since it’s so simple to display project-related information, why not include it all? When an analyst has a large project, creating a single overly complex diagram can be tempting.

However, as one author notes, “If you are using activity charts to define the structure of a workflow, you should not try to explore various levels of activity charts down to their most ‘atomic’ level.” Instead, an analyst should try to present a new diagram for each workflow or, if more applicable, use lanes to present different actors within the same workflow.

Another aspect of these diagrams is that they cannot be used in place of a state diagram or a sequence diagram because “activity diagrams do not provide details about how objects behave or how objects collaborate.” This is not a disadvantage per se, but it is important for an analyst to keep in mind when applying diagrams to their work.

In conclusion, activity diagrams are fairly easy to understand and will be useful for most projects because they clearly and moderately clearly demonstrate how things work.” Unlike many diagramming techniques, activity diagrams also allow for the representation of multiple options and actors within a workflow, and are easy to follow even for non-technical users

Activity Diagram Applications:

This diagram has been extended to specify flows between steps that transmit physical matter (eg, gasoline) or energy (eg, torque, pressure).

• Additional changes allow the diagram to better support continuous behaviors and continuous data flows.
• The UML 2 specification significantly expanded the functions and scale of activity diagrams beyond their previous classification as a special case of state diagrams.
• Today, activity diagrams can be considered as 21st century flowcharts, and UML modelers use activity diagrams to describe it.
• Additionally, these diagrams are useful in the following methods:
• business rules
• Functions that occur in parallel
• Complex chain of multiple use cases
• Software flows and logic control settings
• Procedures with judgment points and alternate flows
• single use cases