Modeling business processes with workflows and tasks

With our data model now fully defined, we shift our focus to modeling the business logic required for the euRent system, specifically the Booking Validation and Confirmation steps identified in our initial requirements.

In Normalized Systems theory, traditional business processes are translated into State Machines using Workflow and Task elements. This concept of separating concerns ensures that each atomic step in the process is clearly defined and tracked.

Integrating the process automation resource

To enable the modeling of workflows within the Micro Radiant, we must first integrate an additional code generation resource into our project. This is the first time in this tutorial that we will extend the base functionality of an NS application by adding external resources. These resources, known as Expansion Resources, allow the core NS application model to generate corresponding code for specific architectural needs (i.e. workflow implementation).

Step 1: Navigate to expansion settings

In the left-hand menu of the Micro Radiant, navigate to the expansion-settings menu.

This screen lists all the resources currently used to generate your application. By default, you will see minimal-jee-beam, which is responsible for generating a backend application based on Java Enterprise Edition (JEE).

Step 2: Add the process automation resource

We need the resource that provides workflow and state machine generation. This is the process-automation resource.

1. Click to add a new resource.
2. Select (or type) the expansion resource named process-automation-beam.
3. Choose the latest suggested version from the list.
4. Confirm your selection.

Once added, a new entry, org.normalizedsystems.beam:process-automation-beam, will appear in your resources list. This action immediately updates the Micro Radiant with new functionality, specifically the option to define Workflow and Task elements.

Step 3: Add a micro radiant plugin

After adding the Expansion Resource, we need also need to add the corresponding Micro Radiant plugin. A plugin extends the Micro Radiant UI with new buttons and views for that specific resource. In our case, the workflow plugin will add buttons to create a new workflow and visualize it.import

1. Navigate to the menu in the top bar of the micro radiant
2. Go to Settings
3. Select Plugins and search for net-democritus-workfow-plugin and validate if the plugin is already activated
4. If not, install the plugin and restart the Micro Radiant

Step 4: Add the process automation component

A new feature might require a component in our application to store data for its inner workings. For example, the base components we previously added, all have a separate component with their data elements.

Navigate to the upper left menu and select one of the base components. This will show a list of data elements, just like our own rentWork component.

1. In the sidebar, select + Component
2. Use processAutomation as name of the component
3. Leave the other

If you know select this processAutomation component in the sidebar (click Show More), you should see the available data elements. (e.g. WorkerNode, TaskJobQueue)

To use this component in our own component rentWork, we have to define a dependency.

1. Select the rentWork component in the sidebar
2. Select + Add new Component Dependency
3. Select processAutomation in the dependsOn dropdown

Creating the booking workflow

A Workflow in NS is a sequence of Tasks operating on a single Data Element and is conceived as a State Machine. In this example, the data element being considered is Booking, for which we will define a workflow.

Step 1: Add a status field

Since a workflow is fundamentally a State Machine, we first need a field on the Data Element to be able to store the current state. In the case of our Booking Validation process, we have to be able to indicate whether the validation process has begun, is in progress, or has been completed.

1. Navigate to the Booking element.
2. Create a new ValueField with the following properties:

• Name: status
• ValueField: ✅
• Type: String
• Option: isStatusField (this option will be read and used by our workflow resource)

Step 2: Define the workflow element

With the status field defined, it is now possible to create the workflow element that manages the state transitions of the Booking.

1. Navigate back to the rentWork component.
2. Select Add workflow from the component menu.
3. Specify the required properties for the BookingFlow:

Name	PackageName	TargetField	Execution
BookingFlow	com.nsx	rentWork::Booking::status	(Leave default value)

By setting the TargetField to rentWork::Booking::status, we configure that this workflow manages the lifecycle of the Booking Data Element, and its status is stored in the status field. A new entry named BookingFlow will now be listed under the Workflows menu.

Completing the state diagram

The next step is to formally define the sequence of States and Transitions for the rental process. We need three core states: a starting state, an intermediate state after validation, and a final state upon confirmation.

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Step 1: Define states

Add the following three user-defined States:

• BookingRequested
• BookingValidated
• BookingConfirmed

Mark BookingRequested as the InitialState. Any new Booking created by a customer will begin in this state.

Step 2: Define transitions

A Transition defines the movement from a BeginState to an EndState via an action. Leave ExecuteTask and EndState.TaskOutcome empty for now. We are only modeling the flow, the actual implementation is modeled in tasks and will be added in the next section.

Name	BeginState	EndState
ValidateBooking	BookingRequested	BookingValidated
ConfirmBooking	BookingValidated	BookingConfirmed

As you create these Transitions, the Micro Radiant automatically generates required intermediate states to handle system processing:

• Interim States: ValidateBookingInProgress, ConfirmBookingInProgress. These are used to show a user that a task is currently executing.
• Failure States: ValidateBookingFailed, ConfirmBookingFailed. These are reserved for tracking failures during task execution, adhering to the NS Separation of States (SoS) principle.

Step 3: Visualizing the workflow

To confirm the structure, click the diagram icon on the right side of the editor and select the workflow view. You should see the full state diagram, including the automatically generated interim and failed states, clearly illustrating the flow logic.