FlowBuilder

Swimlane diagram maker

Show who does each step. Type lane: Team name before a group of steps and FlowBuilder draws a cross-functional flowchart with a lane for every role.

How to write steps
  • One step per line. Lines connect top to bottom.
  • End a line with ? to make a decision. Indent the answers under it: yes: Ship it, no: Refund.
  • Indent more lines under an answer to continue that branch.
  • -> Step name jumps back to an earlier step (a loop). no -> Step name works inside a decision.
  • Start, End, Done or Stop become rounded start/end shapes.
  • Shape tags: [input] [output] [doc] [db] [sub] [manual] [delay].
  • lane: Sales on its own line puts the next steps in a swimlane.
  • Or paste Mermaid code starting with flowchart TD. It’s detected automatically.

Mermaid code for this chart
flowchart TD
  subgraph L1["Customer"]
    direction TB
    n1(["Start"])
    n2[/"Submit a return request"/]
  end
  subgraph L2["Support"]
    direction TB
    n3{"Within the return window?"}
    n4[/"Explain the policy"/]
    n5(["End"])
    n6[/"Send a prepaid label"/]
  end
  subgraph L3["Warehouse"]
    direction TB
    n7["Receive and inspect the item"]
    n8{"Item as described?"}
  end
  subgraph L4["Finance"]
    direction TB
    n9["Refund the customer"]
    n10(["Done"])
  end
  n1 --> n2
  n2 --> n3
  n3 -->|"no"| n4
  n4 --> n5
  n3 -->|"yes"| n6
  n6 --> n7
  n7 --> n8
  n8 -->|"yes"| n9
  n9 --> n10
  n8 -->|"no"| n4

What the lanes add

Same returns process, drawn twice. Switch the lanes on and off and look at the arrows that cross from one lane to another: each is a hand-off, and hand-offs are where work waits and gets lost.

With lanes, the 4 hand-offs jump out: Customer → Support, Support → Warehouse, Warehouse → Support (rejected items) and Warehouse → Finance. Process-improvement teams count these, because every hand-off is a queue.

Or describe it and let AI sort the lanes

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Your text is sent to an AI model through Vercel AI Gateway to draw the chart and isn’t stored by FlowBuilder. The result lands in the editor below, where you can fix anything by hand.

How to draw a good swimlane diagram

  1. List the actors first: people, teams or systems. Each becomes a lane.
  2. Order lanes by who acts first, usually the customer or requester at the top or left.
  3. Put every step in exactly one lane. If two teams do it together, pick the owner.
  4. Keep decisions in the lane of whoever decides.
  5. Read the crossings. Too many arrows between the same two lanes suggests work that should sit with one team.

Swimlanes are a type of process flow chart. The layout style goes back to Geary Rummler and Alan Brache’s 1990 book Improving Performance, which is why they’re also called Rummler–Brache diagrams.

Questions people ask

What is a swimlane diagram?

A swimlane diagram (also called a cross-functional flowchart) is a flowchart split into lanes, one per person, team or system. Each step sits in the lane of whoever does it, so hand-offs between people become visible as arrows crossing lanes.

When should I use swimlanes instead of a normal flowchart?

When more than one person or team is involved and the question is “who does what?”. For a process one person runs alone, a plain flowchart is clearer.

How do I add a lane in FlowBuilder?

Write lane: Name on its own line. Every step after it goes into that lane until the next lane: line. Arrows between lanes are drawn automatically.

How many lanes can a swimlane diagram have?

There’s no hard limit, but more than five or six lanes gets hard to read on one page. Group minor roles together (“Other teams”) or split the process.

Horizontal or vertical lanes?

Both are common. Use the Left → right switch for horizontal flow with stacked lanes, which suits wide slides; Top → down suits documents and phones.

More ways to chart it

Flowchart makerType steps, get a chart. Free, no sign-up.AI flowchart generatorDescribe a process in words.Code to flowchartPaste code or pseudocode.Decision tree makerYes/no questions to an answer.Process flow chart makerWorkflows and process maps.Data flow diagram makerDFDs, level 0 and level 1.