Flowchart, process map or swimlane — which to draw

Flowchart, process map and swimlane diagram use the same symbols and often describe the same work. The differences are about purpose and about what each one chooses to make visible.

Flowchart

The general term. A flowchart shows steps in order with branches at decision points. It can describe anything: a business process, an algorithm, a troubleshooting routine, a recipe.

Choose it when the question is “what happens, and in what order”.

It leaves out who does each step, how long anything takes, and where the work waits.

Process map

A flowchart aimed at examining and improving real work. Same symbols, different intent. A process map is usually drawn left to right, annotated with timings, volumes or owners, and drawn in two versions: how it works now, and how it should work.

Choose it when you are trying to change the process rather than document it.

It adds the measurements that let you argue about the process with evidence rather than opinion.

The reason it is usually laid out left to right is that rework loops then double back visibly against the flow, and rework is generally what you are hunting for.

Swimlane diagram

A flowchart divided into lanes, one per person, team or system. Each step sits in the lane of whoever does it.

Choose it when responsibility is part of the problem, which it very often is.

It makes visible every hand-off. Each arrow crossing a lane boundary is a point where work changes hands, and hand-offs are where things wait, get dropped, or come back.

A process with four steps that crosses lanes six times is usually slower and more fragile than one with ten steps that stays in one lane. A plain flowchart cannot show you that at all.

Which to draw

If you want to	Draw
Write down how something works	A flowchart
Explain an algorithm or logic	A flowchart
Find where a process is slow	A process map, with timings
Show current versus intended	Two process maps, side by side
Show who is responsible	A swimlane diagram
Find hand-off problems between teams	A swimlane diagram
Document a process for automation	BPMN

A reasonable sequence

For a process you are trying to fix, drawing all three in order works well and does not take long.

Start with a plain flowchart to establish the steps, without arguing about owners. Add lanes once the steps are agreed, which usually starts a useful conversation about who really does what. Then add timings to the steps and the gaps, which turns the diagram into something you can make a decision with.

Each version takes a few minutes once the previous one exists, and each one reveals a different kind of problem.

What about BPMN?

BPMN is a stricter notation with a tighter vocabulary: specific shapes for events, tasks and gateways, and rules about how they combine. It is worth the extra discipline when the process will be read by people who were not in the room, or implemented by somebody working from the diagram alone.

For a team working out how their own work happens, a swimlane diagram in ordinary flowchart symbols is usually faster to draw and easier for everyone to read.