What is the difference of swimlane and activity diagram?

Question

Im trying to make an activity diagram , but i see that activity and swimlane diagram is almost the same, the only difference i see that swimlane diagram include many actor in it

i wonder about the activity and swimlane diagram, what is the difference , and when to use activity / swimlane diagram

Answer 1

An activity diagram is a specific UML diagram which can optionally contain swim lanes, but not mandatory. In this sense, an activity diagram can be a swimlane diagram.

The term swimlane diagram is not an UML term. AFAIK it is older than those UML terms, it characterizes all kind of flow charts with swim lanes, from which the "activity diagram with swim lanes" is just the UML variant.

Answer 2

Activity diagrams can use partitions to group actions that share some characteristics. These partitions may graphically be represented as a swimlane (they can also be representend textually). If you cannot make a difference between a “swimlane” and an activity diagram, it may probably be because IT IS an activity diagram with swimlanes.

Business Process modeling diagrams use swimlines to show the organisational responsibility for parts of the process. The most popular notation is BPMN. This notation exist since 2004 and used the concept of pool and swimlanes to represent an organisation and its subdivisions. BPMN has a larger set of symbols and a more specialized semantic, but a subset thereof is close to UML activities both graphically and semantically.

Before BPMN and UML, classical flowcharts or DFD diagrams were often pragmatically partitioned into columns or lines that looked like swimlanes, that had the semantic of swimlines, but without necessarily be called so:

• According to some authors, the concept of multicolumn flowchart dates back to the 40s
• This kind of flowchart was commonly called functional or cross-functional flow charts rather than swimline diagram. The "function" corresponds to the organisational responsibility.
• Some methods preferred to divide the flow-chart by time-line (day 1, day2, ...) when focusing on process optimization.
• A wikipedia article created in 2005 (after BPMN) defines the swimline diagrams as a family of diagrams, but it refers to several authors in the 40s, 80s and 90s using different terminologies and notation variants, and with no authoritative source.

Flowcharts are easily understood, so these kind of diagrams may still be used a lot. If you have the choice, prefer BPMN and UML which have both the advantage of being official standards, and studies have demonstrated that there core symbols are as well understood by business people as flowcharts.