Open-system environment reference model

Open-system environment (OSE) reference model (RM) or OSE reference model (OSE/RM) is a 1990 reference model for enterprise architecture. It provides a framework for describing open system concepts and defining a lexicon of terms, that can be agreed upon generally by all interested parties.

This reference model is meant as an environment model, complementary to the POSIX architecture for open systems. It offers an extensible framework that allows services, interfaces, protocols, and supporting data formats to be defined in terms of nonproprietary specifications that evolve through open (public), consensus-based forums. This reference model served in the 1990s as a basic building block of several technical reference models and technical architectures.

In 1996 this reference model was standardized in the ISO/IEC TR 14252 titled "Information technology -- Guide to the POSIX Open System Environment (OSE)".