This feature would be fantastic for creating a modular environment. The passing of parameters between flows and essentially creating the ability to make functions would make flows an irreplacable asset to my work.
We are now working on this and will release it in the next couple of months.
Based on the number of votes on this, I would consider the solution recommended to not be sufficient. It may work, but I have tried it and been unsuccesful.
I would also add that if the HTTP action is the recommended way of doing this, it needs to be renamed.
I would like to see this. It would enhance our ability to reuse flows.
Nintex has offer that powerful feature for years. It allows to create smaller modular flows that are easy to restarts, versus having a very long and complex flow. Please allow parameters being passed when launching a sub flow.
It would be helpful to be able to have flows operate more in a modular fashion. I repeat a lot of actions when a flow is very similar. Plus, you cannot copy from one to another so it makes repeating actions to other flows very time consuming and error prone. Save As only accounts for some.
You can do this, and it's not as hard as you think.
Whatever Flow you want to launch from another Flow, you have to start with an HTTP trigger. Once you save your Flow, you'll have be able to see the Url for the HTTP endpoint that can trigger your Flow. Copy it.
Go to the Flow you want to use to trigger your new Flow. Add an HTTP request/response action. Paste in the Url. Use "Post" method.
The most intimidating part is the JSON schema. It can be extremely simple, though. Eg:
"parameter_name_of_your_choice": your dynamic content
That's all you need in your triggering Flow. Notice that the line in between the brackets is "indented" with a single space. In the Flow being triggered, you need to define a schema. There's an option to generate based on a sample payload. All you have to do is type an example, like the one above (or yours can be more complicated if, say, you want to pass in 10 parameters), and let Flow generate the schema for you. Each of those parameters will be available in dynamic content after that, so you can do whatever you want with them from there.