Architecture of Interoperable Information Systems

The Architecture of Interoperable Information Systems (AIOS) is a reference architecture for the development of interoperable enterprise information systems. If enterprises or public administrations want to engage in automated business processes with other organizations, their IT systems must be able to work together, i.e. they need to be interoperable. The AIOS represents a generic building plan for these organizations to develop interoperable information systems by systematically adjusting and extending their internal information systems.
The AIOS was described in a doctoral thesis and is based on the results of various research projects on interoperability. It is independent from specific products or vendors but describes generically the different layers, views, relationships and technical means needed to efficiently establish interoperable information systems. To this aim it combines concepts from service-oriented architecture, Collaborative Business and Business Process Modelling. It can be seen as complementary to ARIS, a well-known architecture for internal information systems and business processes.
Definition.
Similar to the automation of processes inside organizations, the automation of cross-organizational business processes is an important trend. In this endeavor, collaborating organizations rather strive for a loose coupling of their information systems instead of a tight integration: the collaborating information systems should be able to work together but retain as much independency as possible. This characteristic is also called interoperability, or in the context of collaborating organizations, Business Interoperability, i.e. the capability of autonomous organizations to execute a collaborative business process among them.
Information systems are systems that process information, i.e. they capture, transport, transform, store and offer information. Following the conception prevailing in information systems research, an information system comprises not only the hardware and software of an enterprise, but also the related human actors, business functions and processes as well as organization structures. This broad understanding is for example also embodied by the Zachman Framework.
Architecture is defined as the “fundamental organization of a system, embodied in its components, their relationships to each other and the environment, and the principles governing its design and evolution”. Sinz defines an information system architecture as the building plan of an information system in the sense of a specification and documentation of its components and their relationships covering all relevant viewpoints as well as the constructions rules for the creation of the building plan.
Accordingly, an Architecture of Interoperable Information Systems can be defined as the building plan of a cross-organizational information system, which enables organizations to execute a collaborative business process among them.
Background and Application.
Following the work on interoperable information systems conducted in European Research Projects in 2010 the Architecture of Interoperable Information Systems (AIOS) was published as a reference for the construction of loosely coupled, interoperating information systems and for the systematic, model-based enactment of collaborative business processes.
The AIOS aims primarily at large organizations that want to interoperate with each other. To this aim it describes how internal information system elements can be systematically connected with the information systems of collaboration partners. The main elements of the AIOS are:
One element comprised in the third category is a "BII-repository", in which each organization publishes the content of its Business Interoperability Interface (BII) to collaboration partners. Since it comprises external views on information system elements, it provides publishing and discovery functionalities as needed in service-oriented architecture: In the BII, the externally relevant processes, services, organization structures etc. are described on various levels of technical granularity, enabling other organizations to search also for business-level elements and not only for technical artifacts. Here, different from the traditional SOA approach, instead of one central service directory, various partner-specific repositories are implemented.
Structure.
The static part of the architecture builds on three orthogonal axes: Enterprise Dimensions, Levels of technical Granularity and Colloborative Views.
Collaborative views.
Similar to private, public and global views as known from business process and workflow modeling, in the AIOS, corresponding private, public and global views on information system elements are provided.
Enterprise dimensions.
To describe business processes comprehensively this axis provides distinct views on processes, functions, data, and organizational elements. 
Thus, in combination with the axis "collaborative views", private, public and global views on processes, functions, data, and organizational roles are provided.
Levels of technical granularity.
The description of system elements on different levels of technical granularity supports a systematic development of collaborative information systems, starting with the business requirements definition and going all the way down to the code level. Apart from the construction aspect, thereby also a multi-dimensional interoperability description is provided, facilitating the synchronization of collaborating systems on each level. Similar to for example ARIS and OMG's MDA three levels are used: