The Eclipse MDM|BL comprises a bottom to top architecture view of three parts.
The first one is a specific openMDM application model definition for the ASAM ODS data storage. The standardization provides a structured representation for common use case related data in all openMDM application. The data model is split into the base model, which covers the most common use cases, and extensions for additional use cases.
The base model and every extension has an associated API interface. These interfaces are used by higher level components to work with openMDM business objects. In addition there are a set of business interfaces, which represent non data based enterprise use cases.
At the top of the layer there are the implementations of the business interfaces. In consideration of the API there normally will be an ODS server implementation but in some use cases the data storage is implemented otherwise. Virtual objects or the storage in an ODS ATFX file are examples.
Concerning the runtime view the business layer project defines a core application structure, which every openMDM application is based on. This structure is composed of services and rules how these services should be used and be executed at runtime.