This document specifies the fundamental characteristics of the computational model implemented by a specific architectural layer of the information system (i.e. the service architecture) to provide a comprehensive and integrated interface to the common enterprise information and to support the fundamental business processes of the healthcare organization, as defined in ISO 12967‑1. The computational model is specified without any explicit or implicit assumption about the physical technologies, tools or solutions to adopt for its physical implementation in the various target scenarios. The specification is nevertheless formal, complete and non-ambiguous enough to allow implementers to derive an efficient design of the system in the specific technological environment which will be selected for the physical implementation.

The computational model specified in this document provides the basis for ensuring consistency between different engineering and technology specifications (including programming languages and communication mechanisms) since they are intended to be consistent with the same computational object model. This consistency allows open inter-working and portability of components in the resulting implementation.

This document does not aim at representing a fixed, complete, specification of all possible interfaces that might be necessary for any requirement of any healthcare enterprise. It specifies only a set of characteristics — in terms of overall organization and individual computational objects, identified as fundamental and common to all healthcare organizations, and that are satisfied by the computational model implemented by the service architecture.

Preserving consistency with the provisions of this document, physical implementations of the computational model specified in this document can allow extensions in order to support additional and local requirements. Extensions can include both the definition of additional properties of the objects of the computational model specified in this document and the implementation of entirely new objects.

Also, the computational model specified in this document can be extendable over time according to the evolution of the applicable standardization initiatives, in accordance to the methodology defined in ISO 12967‑1:2020, Clause 7, which identifies a set of healthcare common information services, describing the requirements behind them and the methodology through which they will be used.

The information services specified in this document are only the minimal set identifiable according to the identified requirements of the healthcare enterprise, and constituting the service architecture (i.e. the integration platform) to serve as the basis for healthcare applications, e.g. EHR or patient administration.