Introduction

A workflow in PIPEFORCE is a stateful business process where one or more humans are involved. Workflows can be modelled using a graphical interface and they can optionally trigger the execution of pipelines.

Workflow design with BPMN

In PIPEFORCE workflows can be designed using BPMN (Business Process Model and Notation) which is a worldwide ISO standardization to describe business processes in a formalized (graphical) way. Also most non-technicals can understand BPMN diagrams. If you’re not familiar with BPMN so far, we highly recommend you to learn more about it before you dive deeper into this chapter. Here you can find a first introduction on Wikipedia: Business Process Model and Notation.

Below is a very simple example of such a BPMN diagram which shows a vacation approval process where the employee must fill-out a request form and the supervisor then can approve or decline the vacation request:

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A simple vacation request BPMN diagram

BPMN digrams are designed using a BPMN designer tool. You can use your own local software to design such a diagram and then upload them to PIPEFORCE or you can use the built-in online BPMN designer from PIPEFORCE. With the later you can:

• Create BPMN diagrams online in your web browser and save the

• Discuss a BPMN diagram with your team

• Link BPMN tasks with pipeline

• Directly execute and review BPMN diagrams as workflows

Most important BPMN diagram elements

In order to draw a BPMN diagram, the most important elements are these, you should be aware of:

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The User Task

The user task is the part of a workflow in case an input from a user is required. The workflow waits at this point until the user has finished this task by clicking “Complete”.

The input of the user is typically given by filling-out a form.

The form can be defined using the “Forms” tab in the modeller.

The System Task

If a task in the workflow must be executed by a “machine”, for example sending an email, doing a conversion or creating a new data set, typically a System Task is used for this.

By default a pipeline is used to execute such a system task.

To configure a system task to execute such a pipeline, you need to make sure, you have these settings in place:

1. The task type is set to a System Task.

2. The Implementation is set to Delegate Expression.

3. The Delegate Expression is set to ${pipelineDelegate}.

To execute a pipeline, you have two configuration options:

1. Calling a pipeline embedded into the User task as parameter.

2. Calling a pipeline stored in the property store.

Call an embedded pipeline

In order to trigger an embedded pipeline whenever the system task is executed, you can define a new input parameter with name pipeline of type Text and add the pipeline directly as value:

Call a pipeline stored in the property store

Lets assume, a pipeline is stored in the property store under this key path:

Then, you need to configure your System Task like this to automatically pick-up and execute this pipeline in case the system task is executed by the workflow:

1. Make sure the Id of the BPMN workflow is the same name as the app: vacation-request.

2. Make sure the Id of the System Task which should execute the pipeline has the same name as the pipeline: myPipeline.

3. Do not define any pipeline parameter in the System Task.

When executed, the System Task automatically searches for a pipeline in given app folder and executes it.

How to start a workflow in PIPEFORCE?

The design and execution of a workflow in PIPEFORCE is always a 3-steps task:

1. Design the workflow in the BPMN modeler and save the result. When you work locally with the pi tool, save it at: app/myApp/workflow/myWorkflow.bpmn.

2. Deploy by pushing the DEPLOY button in the online designer or upload the BPMN file using the pi tool by calling the command: pi publish.

3. Execute the workflow using the command workflow.start in a pipeline and set as parameter key the Id of your process (see BPMN file). You can use for example the pi tool to start a workflow:
   pi uri ”workflow.start?key=<ID>”

Then you can login to your portal at https://<NAMESPACE>.pipeforce.net and complete the workflow.