It is a common observation that a business scenario is captured by multiple process models on different abstraction levels. Depending on the purpose of the model, not only the level of abstraction, but also the adopted perspective is different between these models. Therefore, alignment of these models is of key importance but far from trivial.

Let us have a look at the exemplary scenario captured in the two models above. The upper model expresses the fact that a staff member receives a certain request and handles it immediately. Thus, the process instance is created with the reception of the request and ends with the completion of the request handling. As this model gives you a high-level view on the business case, we refer to it as a business model.

On the other hand, the lower model is more fine grained and assumes a technical perspective. It expresses the fact that the request handling system collects all accumulated requests. Afterwards every request is scheduled for handling and acknowledged separately. This model is less abstract than the other one as it focuses on the reception of requests and does not cover the actual handling. Therefore, we refer to this model as a workflow model.

We see that both models describe the same business case on different abstraction levels. In addition the models assume different perspectives. In real world scenarios, more than two abstraction levels and two perspectives might be involved. However, we focus on the alignment of two model layers, business models and workflow models, in the context of this survey. Different abstraction levels and different perspectives impose challenges regarding an alignment. What kind of model relation must be established between these models in order to guarantee a certain consistency between them or propagate changes efficiently?