How to Merge Paths in BPMN with a Gateway (Visio Step by Step)
A BPMN gateway can split a process and join it back together. Learn how to merge two paths with a gateway in Visio, and why every outgoing flow of a split needs a label, with an order fulfilment example.
Step by step
- Merge paths in BPMN. A gateway splits a BPMN process into paths. A second gateway joins them back together. This example draws it in Visio with the BPMN shapes, using an order fulfilment process.
- The start. Drop a Start Event and type Order received. This is what starts the process.
- Split gateway. Drop a Gateway next to it and give it one clear question: In stock? Connect the start event to the gateway with a Sequence Flow.
- Label each path. Drop a Task for the yes path and name it Pick from shelf. This is where the warehouse picks the item. Connect the gateway to it with a Sequence Flow and label the flow Yes. Drop a second Task for the no path and name it Order from supplier. This is where purchasing buys the item in. Connect the gateway to it and label this flow No. Now every flow out of the split shows which answer it stands for.
- Merge gateway. Drop another Gateway between the two paths, after the tasks. Leave it without text, because a merge asks no question. It passes on whichever path arrives. Connect Pick from shelf down into the merge gateway. Then connect Order from supplier up into the same gateway. Both paths now meet at one point.
- One way on. After the merge there is only one way on. Drop a Task named Pack order. Connect the merge gateway to Pack order with a single Sequence Flow.
- End event. Finish with an End Event and type Order packed. Connect Pack order to the end event with the last Sequence Flow.
- Done. Click an empty part of the page so nothing is selected. Now you can see the whole diagram, with the split and the merge.
- The rule. The rule: a split gateway asks a question, and every path out of it gets a label. A merge gateway asks nothing. It just brings the paths back together.
Common mistakes
- Merging either/or paths with a parallel gateway. A parallel gateway (the + shape) waits until every incoming path arrives. Only one of Yes or No ever runs, so the process gets stuck there. Merge with the same kind of gateway you split with.
- Leaving the split's flows unlabelled. Without Yes and No on the flows, readers can't tell which path is which. Select each Sequence Flow coming out of the split and type its label.
- Putting a question on the merge gateway. A merge decides nothing, so text like In stock? on it makes readers think there is a second decision. Leave the merge gateway blank.
- Connector ends not attached to the shapes. If a Sequence Flow is not glued to a shape, it gets left behind when you move that shape, and the diagram no longer joins up. Drop each end of the connector right onto the shape so it attaches.
When a business analyst uses this
In a current-state process map drawn in a workshop, a credit check sends a loan application down an Approve path or a Refer path. A merge gateway brings both paths back to Send decision letter. Stakeholders then see one shared ending to sign off, not the same steps copied twice.
Questions people ask
Do you need a gateway to merge paths in BPMN?
Not always. BPMN lets 2 flows go straight into a task. But a merge gateway is clearer, and you need one to join parallel paths properly.
What is the difference between a split gateway and a merge gateway?
A split has one flow in and several flows out. It asks a question, and each path gets a label. A merge has several flows in and one flow out, and it asks nothing.
Do the flows out of a gateway need labels?
On a split, yes. Label each flow with the answer it stands for, like Yes and No. The flow out of a merge needs no label, because there is only one.
