Open System Environment Reference Model
Encyclopedia
Open-system environment (OSE) reference model (RM) or OSE reference model (OSE/RM) is one of the first reference model
s 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.
Two types of elements are used in the model: entities consisting of the application software, application platform, and platform external environment; and interfaces including the application program interface and external environment interface.
(IEEE). This model wanted to address interoperation for a communications, computing, and entertainment infrastructure. The OSE/RM is also identified at the international level in Joint Technical Committee 1 (JTC1) Technical Report (TR) 14250. A profile by the NIST (1996) identifies some standards that can be adapted to the identified OSE services.
The NIST has hosted workshops and conducts other support activities to assist users in addressing open systems requirements, preparing for the use of new technology, and identifying the international, national, industry and other open specifications that are available for building open systems frameworks, such as the government's applications portability profile for the open-system environment. NIST sponsors the semiannual Users' Forum on Application Portability Profile (APP) and Open System Environment (OSE) to exchange information and respond to NIST proposals regarding the evaluation and adoption of an integrated set of standards to support the APP and OSE. The quarterly Open Systems Environment Implementors' Workshop (OIW), co-sponsored by NIST and the Institute of Electrical and Electronics Engineers
(IEEE) Computer Society, provides a public international technical forum for the timely development of implementation agreements based on emerging OSE standards.
In its simplest form, the OSE/RM illustrates a straightforward user-supplier relationship: the application software is the user of services and the application platform/ external environment entities are the suppliers. The API and EEI define the services that are provided.
An OSE profile is composed of a selected list of open (public), consensus-based standards and specifications that define services in the OSE/RM. Restricting a profile to a specific domain or group of domains that are of interest to an individual organization results in the definition of an organizational profile.
The services defined in the APP tend to fall into broad service areas . These service areas are:
Each service area is defined in the following sections. The figure illustrates where each of these services areas relates to the OSE/RM. Assume that software engineering
services are applicable in all areas. Each of the APP service areas addresses specific components around which interface, data format, or protocol specifications have been or will be defined. Security and management services are common to all of the
service areas and pervade these areas in one or more forms.
identifies and describes the types of applications, platforms, and external entities; their interfaces; and their services; as well as the context within which the entities interoperate. A technical architecture is based on a technical reference model (TRM) and the selected standards that further describe the TRM elements (the profile). The technical architecture is the basis for selecting and implementing the infrastructure to establish the target architecture.
A technical reference model can be defined as a taxonomy of services arranged according to a conceptual model, such as the Open System Environment model. The enumerated services are specific to those needed to support the technology computing style (e.g., distributed object computing) and the industry/business application needs (e.g., Human Services, financial).
Reference Model
A reference model in systems, enterprise, and software engineering is a model of something that embodies the basic goal or idea of something and can then be looked at as a reference for various purposes.- Overview :...
s for enterprise architecture
Enterprise architecture
An enterprise architecture is a rigorous description of the structure of an enterprise, which comprises enterprise components , the externally visible properties of those components, and the relationships between them...
. It provides a framework
Software framework
In computer programming, a software framework is an abstraction in which software providing generic functionality can be selectively changed by user code, thus providing application specific software...
for describing open system
Open system
Open system may refer to:*Open system , one of a class of computers and associated software that provides some combination of interoperability, portability and open software standards, particularly Unix and Unix-like systems...
concepts and defining a lexicon of terms, that can be agreed upon generally by all interested parties.
Overview
The open-system environment (OSE) forms 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. A selected suite of specifications that defines these interfaces, services, protocols, and data formats for a particular class or domain of applications is called a profile.Two types of elements are used in the model: entities consisting of the application software, application platform, and platform external environment; and interfaces including the application program interface and external environment interface.
History
The open-system environment reference model (OSE/RM) refines the core POSIX model defined by the POSIX Working Group 1003.0 of the Institute of Electrical and Electronics EngineersInstitute of Electrical and Electronics Engineers
The Institute of Electrical and Electronics Engineers is a non-profit professional association headquartered in New York City that is dedicated to advancing technological innovation and excellence...
(IEEE). This model wanted to address interoperation for a communications, computing, and entertainment infrastructure. The OSE/RM is also identified at the international level in Joint Technical Committee 1 (JTC1) Technical Report (TR) 14250. A profile by the NIST (1996) identifies some standards that can be adapted to the identified OSE services.
The NIST has hosted workshops and conducts other support activities to assist users in addressing open systems requirements, preparing for the use of new technology, and identifying the international, national, industry and other open specifications that are available for building open systems frameworks, such as the government's applications portability profile for the open-system environment. NIST sponsors the semiannual Users' Forum on Application Portability Profile (APP) and Open System Environment (OSE) to exchange information and respond to NIST proposals regarding the evaluation and adoption of an integrated set of standards to support the APP and OSE. The quarterly Open Systems Environment Implementors' Workshop (OIW), co-sponsored by NIST and the Institute of Electrical and Electronics Engineers
Institute of Electrical and Electronics Engineers
The Institute of Electrical and Electronics Engineers is a non-profit professional association headquartered in New York City that is dedicated to advancing technological innovation and excellence...
(IEEE) Computer Society, provides a public international technical forum for the timely development of implementation agreements based on emerging OSE standards.
OSE reference model entities
The three classes of OSE reference model entities are described as follows:- Application software : Within the context of the OSE Reference Model, the application software includes data, documentation, and training, as well as programs.
- Application platform : The application platform is composed of the collection of hardware and software components that provide the generic application and system services.
- Platform external environment : The platform external environment consists of those system elements that are external to the application software and the application platform (e.g., services provided by other platforms or peripheral devices).
Classes of interfaces
There are two classes of interfaces in the OSE reference model: the application program interface and the external environment interface:- Application programming interfaceApplication programming interfaceAn application programming interface is a source code based specification intended to be used as an interface by software components to communicate with each other...
(API) : The API is the interface between the application software and the application platform. Its primary function is to support portability of application software. An API is categorized in accordance with the types of service accessible via that API. There are four types of API services in the OSE/RM:- Human/computer interface services
- Information interchange services
- Communication services
- Internal system services
- External environment interface (EEI) : The EEI is the interface that supports information transfer between the application platform and the external environment, and between applications executing on the same platform. Consisting chiefly of protocols and supporting data formats, the EEI supports interoperability to a large extent. An EEI is categorized in accordance with the type of information transfer services provided.
Types of information transfer services
There are three types of information transfer services. These are transfer services to and from:- Human users
- External data stores
- Other application platforms
In its simplest form, the OSE/RM illustrates a straightforward user-supplier relationship: the application software is the user of services and the application platform/ external environment entities are the suppliers. The API and EEI define the services that are provided.
OSE profile
A profile consists of a selected list of standards and other specifications that define a complement of services made available to applications in a specific domain. Examples of domains might include a workstation environment, an embedded process control environment, a distributed environment, a transaction processing environment, or an office automation environment, to name a few. Each of these environments has a different cross-section of service requirements that can be specified independently from the others. Each service, however, is defined in a standard form across all environments.An OSE profile is composed of a selected list of open (public), consensus-based standards and specifications that define services in the OSE/RM. Restricting a profile to a specific domain or group of domains that are of interest to an individual organization results in the definition of an organizational profile.
APP service areas
The Application Portability Profile (APP) is an OSE profile designed for use by the U.S. Government. It covers a broad range of application software domains of interest to many Federal agencies, but it does not include every domain within the U.S. Government’s application inventory. The individual standards and specifications in the APP define data formats, interfaces, protocols, or a mix of these elements.The services defined in the APP tend to fall into broad service areas . These service areas are:
- Operating system services (OS)
- Human/computer interface services (HCI)
- Data management services (DM)
- Data interchange services (DI)
- Software engineering services (SWE)
- Graphics services (GS)
- Network services (NS)
Each service area is defined in the following sections. The figure illustrates where each of these services areas relates to the OSE/RM. Assume that software engineering
Software engineering
Software Engineering is the application of a systematic, disciplined, quantifiable approach to the development, operation, and maintenance of software, and the study of these approaches; that is, the application of engineering to software...
services are applicable in all areas. Each of the APP service areas addresses specific components around which interface, data format, or protocol specifications have been or will be defined. Security and management services are common to all of the
service areas and pervade these areas in one or more forms.
Applications
Basically the open-system environment model is a basic building block of several technical reference models and technical architecture. A technical architectureTechnical architecture
Technical architecture is one of several architecture domains that form the pillars of an enterprise architecture or solution architecture. It describes the structure and behaviour of the technology infrastructure of an enterprise, solution or system...
identifies and describes the types of applications, platforms, and external entities; their interfaces; and their services; as well as the context within which the entities interoperate. A technical architecture is based on a technical reference model (TRM) and the selected standards that further describe the TRM elements (the profile). The technical architecture is the basis for selecting and implementing the infrastructure to establish the target architecture.
A technical reference model can be defined as a taxonomy of services arranged according to a conceptual model, such as the Open System Environment model. The enumerated services are specific to those needed to support the technology computing style (e.g., distributed object computing) and the industry/business application needs (e.g., Human Services, financial).
See also
- Enterprise architecture framework
- Federal enterprise architectureFederal Enterprise ArchitectureA federal enterprise architecture is the enterprise architecture of a federal government. It provides a common methodology for information technology acquisition, use, and disposal in the Federal government....
- GERAM
- TAFIMTAFIMTechnical Architecture Framework for Information Management is a 1990s reference model for enterprise architecture development, defined by the United States Department of Defense in 1986....
- TOGAFTOGAFThe Open Group Architecture Framework is a framework for enterprise architecture which provides a comprehensive approach for designing, planning, implementation, and governance of an enterprise information architecture...
Further reading
- Department of Defense (1996). Technical Architecture Framework for Information Management. Vol. 2, Technical Reference Model.
- Defense Information Systems Agency (2001). DoD Technical Reference Model, Version 2.0, April 9, 2001.
- Gary Fisher (1993). Application Portability Profile (APP) : The U.S. Government’s Open System Environment Profile OSE/1 Version 2.0. NIST Special Publication 500-210, June 1993.
- IEEE P1003.22 Draft Guide for POSIX Open Systems Environment—A Security Framework