Open systems architecture, in telecommunication, is a standard that describes the layered hierarchical structure, configuration, or model of a communications or distributed data processing system that:
Enables system description, design, development, installation, operation, improvement, and maintenance to be performed at a given layer or layers in the hierarchical structureAllows each layer to provide a set of accessible functions that can be controlled and used by the functions in the layer above itEnables each layer to be implemented without affecting the implementation of other layersAllows the alteration of system performance by the modification of one or more layers without altering the existing equipment, procedures, and protocols at the remaining layersOpen systems architecture may be implemented using the OSI Model as a guide while designing the system to meet performance requirements.