You have already identified the process components and deployment units required and created them in the modeling environment.
More information: Integration Scenario Model
In the modeling environment create an integration scenario model type model (SAP integration scenario model).
Add the required deployment units to the model.
Add the required process components to the model. Make sure that you model the process from left to right.
Connect the process components together using interactions. Only direct interactions are permitted within a deployment unit.
Recommendation
Some process components are of such importance that you need to connect them to almost every other process component (for example, Accounting). This, however, gives an incorrect impression of the actual process flow. Work with placeholders in the integration scenario model to avoid this. Only connect the placeholder with a process component if the interaction is essential for the understanding of the end-to-end business scenario.
You can assign Enterprise Service interaction type interactions using the
context menu to an existing process components interaction model (SAP ProComp Model) or create a new interaction model from this interaction. In this last case, the modeling environment adds the process components associated with communication directly to the new interaction model.More information: Process Components Interaction Model