Interview Questions for Business Analysts and Systems Analysts

Recent Interview Questions | Search | Subscribe (RSS)


What is a Swimlane Diagram?


A swimlane diagram (also sometime called a cross-functional diagram) documents the steps or activities of a process flow or workflow.  More specifically, a swimlane diagram groups these activities into swimlanes which are horizontal or vertical columns that contain all of the activities which fit into the category represented by that swimlane.  Swimlanes can represent many categories of information such as actors which perform the activities (i.e., role or department), the stage of the process in which the activity takes place, or whatever else the creator of the document feels should be emphasized and communicated by the swimlane diagram.  The term swimlane was adopted due to the visual similarity between the horizontal rows of the diagram to that of the swimlanes found within a swiming pool.

What is a Swimlane Diagram?

A process flow or workflow diagram does not have to use swimlanes.  However, since swimlanes communicate additional information about who performs the activity or when it takes place, it’s typically a preferred best practice to include them.  Similarly, a swimlane diagram can use only one set of swimlanes (either vertical swimlanes or horizontal swimlanes).  In BPMN standards, a process flow is typically shown flowing from left to right.  If only one set of swimlanes is used, horizontal swimlanes are most commonly used to group activities.  In the UML standard, the activity diagram flows from top to bottom and veritcal swimlanes are most commonly used.   

One of the more common choices used by creators of swimlane diagrams is to define the roles which perform each activity within horizontal swimlanes and define the process stages in which the activity occurs within vertical swimlanes.



Putcha posted on Monday, July 4, 2011 11:03 PM
Good explanation. Howerver, "swimlane diagram" is not a commonly phrase. Swimlanes are shown in UML Activity Diagrams or BPMN diagrams.

[email protected]
vr posted on Monday, January 2, 2012 11:21 AM
When swimlane diagrams are used and in which document we will use this?
Adrian M. posted on Thursday, January 5, 2012 2:02 AM
Swimlane diagrams are used whenever you need to show activities, tasks, or process steps which are being performed by different actors/roles.

You can use swimlanes to group activities in an activity diagram or process flow by any category what you need: by role, by system, by department, etc.

As to which document should include a swimlane diagram or activity diagram, that depends on your need. For example, if you are using the diagram to show a target state process at the high level then you may include the diagram in a project's charter or vision document. If the diagram is more detailed then the swimlane diagram might be part of your requirements document.
Adrian M.
schavalla posted on Tuesday, November 13, 2012 3:50 AM
@ Putchavn

we can call swimlane diagrams as partition in the business use cases which denotes, different actors involved involved in particular process in achieving single goal.
TKhan posted on Tuesday, March 19, 2013 5:12 AM
Can anyone tell me when to use Horizontal and Vertical swimlane in diagrams??
Bill Crisp posted on Saturday, March 30, 2013 1:36 AM
Mrs. Ellen Gottesdeiner, in her work The Software Requirements Memory Jogger, indicates that a Flowchart or Process Map are drawn sideways, rather than top to bottom (p. 175). These are alternatives techniques to an Activity Diagram (top to bottom).

She provides that alternative names for the process map are: Swimlane Diagram, Cross-Functional Process Map, and Line of Visibility Model (LOVEM), p. 122.

Barbara Carkenord, in her work Seven Steps to Mastering Business Analysis, calls these Workflow Diagrams and also displays an example with a left-to-right (sideways) orientation. "A workflow diagram can be divided into sections to show departments or divisions within an organization. These sections are referred to as swim lanes. The UML shapes vary a bit from ANSI for use in the UML activity diagram" (2009, p. 193).

I found the following helpful. Dianne Galloway, in Mapping Work Processes, posits that "Flowcharts may run either vertically or horizontally. Make this vertical/horizontal choice based on the amount and nature of the wall or table space available to you." (1994, p. 36). All her examples in the book have a north-south orientation. That is, with the actors/roles/organizations portrayed at the top.

The Second Edition of this same book provides a simpler perspective: "Select a graphical presentation format that suits your purpose. Basic flowcharts can be formatted in many different ways; they do not have to look like the example in Figure 6.3 [north-south orientation]. The main idea behind a basic flowchart is to make it simple as you can a slong as the map is constructed in a way that support your purpose." (2008, p. 52). The four authors of this work clearly prefer the vertical swim lanes, as illustrated in all their examples.

It's clear that published authors have varying opinions as to which orientation should be used. Thus, I would recommend that we revisit the purpose of these diagrams, and that is to simply come to a common understanding of the process and/or requirements. As long as the provider and customer derive the same meaning from these diagrams, use whatever orientation best meets that objective. I would offer that there's no pat industry standard for the direction used and even if there were, it means nothing if you or your customer don't inherently know that. This is much the same as which objects are used in diagrams. You don't look smarter with your team or customers by adding each UML/BPMN object under the sun. Rather, it merely promotes confusion.
Bill Crisp
Only registered users may post comments.

Do your homework prior to the business analysis interview!

Having an idea of the type of questions you might be asked during a business analyst interview will not only give you confidence but it will also help you to formulate your thoughts and to be better prepared to answer the interview questions you might get during the interview for a business analyst position.  Of course, just memorizing a list of business analyst interview questions will not make you a great business analyst but it might just help you get that next job.



Select ModernAnalyst Content

Register | Login

Copyright 2006-2024 by Modern Analyst Media LLC