COEPD – Center of Excellence for Professional Development Happy Learning
Activity Diagram
An activity diagram visually presents a series of actions or flow of control in a system similar to flow chart or a data flow diagram.
An activity diagram is drawn to model how the system should function in order to achieve Business Logic, Business Functionality and Business Objectives.
Activity diagram used in BPM (Business Process Modelling). Activity diagram clearly displays flow of a control which is mentioned in USECASE diagram.
Activity Diagram helps developers to understand in a clear manner of requirement in a UML (Unified Modelling Language). Activity diagram is the dynamic view of UML. An operation of the system can be described with help of activity diagram. Activity diagram used to construct the executable system by using forward and reverse engineering techniques
MS VISIO is used to draw Activity Diagram and which is drag and drop method
In activity diagram there were few drawing elements
: Indicates where work flow will starts
: Arrow showing direction of workflow. Generally, control flow will start from top to
Bottom and from left to right
: Indicates steps in the process. It is the unit of work done by the system or a
Consistent state achieved
: Indicates a choice. Workflow will proceed along one of a number of possible
Paths, according to the guard conditions
: Indicates where work flow will end
: A condition attached to control flow. When the guard condition is true,
Workflow may flow along the control flow. Guard conditions are usually
Attached to control flows that came out of a decision symbol. A guard
Condition shown within square brackets
: An event must occur for the flow to
Move along the control flow. Event is externally triggered
Or it can be a consistent point of a defined time frame
: Between a branch and Merge, we can have many number of paths. For the
Control to pass from branch to merge at least minimum one path should
Execute.
Eg: Payment by cash, card, net banking coupons
: Between a Fork and Join, we can have n number of paths. For the control to
Pass from Fork to join all the paths should execute. The condition between
The paths will be “AND”
Eg: Cash withdrawal from ATM
Nested Loop Activity: This is an activity wherein this activity may contains series of activities
Internally
Connector: A Connector has multiple inputs and multiple outputs. Practically we use
Connectors for 1- many and many – 1
Continuation Node: If activity is big and is spanning pages. We give continuity from one page
Through another page by using continuation nodes. It can also be used to
Connect extreme left to right sides in a page or for reusability of a
Particular flow
Few Important Points related to Activity Diagram:
- Activity Diagrams can be drawn as below levels like
- Project wise, module wise, department wise, functionality wise, use case wise
- Activity Diagrams can be drawn based on frequency
- Setup, 1 Time, Annual, Half-yearly, Quarterly, Monthly, Weekly, Daily, Predefined frequency and adhoc basis- specific to an initiative
- We can draw multiple activity diagrams for a single case study where as it will be only one case diagram
- If we are drawing multiple activity diagrams for a single case study every diagram should have a heading based on level and time frequency
