# Call existing work

> The categories of the Add node panel that call work that already exists: Maestro Flow, Maestro BPMN, Maestro Case, RPA Workflow, API Workflow, and Function.

The categories **Maestro Flow**, **Maestro BPMN**, **Maestro Case**, **RPA Workflow**, **API Workflow**, and **Function** (Preview) call work that already exists: another workflow, a process, a robot, or code. Each one offers **In this solution**, for items in the same solution, and **Published**, for items deployed in your organization.

![The RPA Workflow category, with In this solution and Published.](https://dev-assets.cms.uipath.com/assets/images/maestro-automate/add-node-rpa-automate-d25e4a77.webp)

- [Maestro Flow](maestro-flow-nodes.md): calls another workflow, or groups nodes into a subflow.
- [Maestro BPMN](node-bpmn-process.md): calls a Business Process Model and Notation (BPMN) process.
- [Maestro Case](node-maestro-case.md): calls a case, long-running work about one situation, such as a claim, built on the Case canvas.
- [RPA Workflow](node-rpa-workflow.md): runs a robot automation and waits for it to finish.
- [API Workflow](node-api-workflow.md): calls an API workflow and uses its result.
- [Function](node-function.md) (Preview): runs a coded function.

## Next steps

- [Node reference](flow-node-reference.md): all the categories of the **Add node** panel.