Generalised Enterprise Reference Architecture and Methodology


Generalised Enterprise Reference Architecture and Methodology is a generalised enterprise architecture framework for enterprise integration and business process engineering. It identifies the set of components recommended for use in enterprise engineering.
This framework was developed in the 1990s by a joint task force of both the International Federation of Automatic Control and the International Federation of Information Processing on enterprise architectures for enterprise integration. The development started with the evaluation of then-existing frameworks for enterprise application integration, which was developed into an overall definition of a so-called "generalised architecture".

Overview

One of the basics of GERAM is that enterprise modelling was seen as the major issue in enterprise engineering and integration. It contained several of building blocks, in which the methodologies and the corresponding languages have been implemented, such as:
  • Enterprise modelling tools to support the enterprise integration process.
  • Ontological theories,
  • Generic enterprise models and
  • Generic modules
The building blocks were designed to support the modelling process by providing means for more efficient modelling.
The resulting enterprise model represents all or part of the enterprise operation. These models will allow simulation of operational alternatives and thereby their evaluation leading. GERAM provides a generic description of all the elements recommended in enterprise engineering and integration.
Generalised Enterprise Reference Architecture and Methodology is an enterprise-reference architecture that models the whole life history of an enterprise integration project from its initial concept in the eyes of the entrepreneurs who initially developed it, through its definition, functional design or specification, detailed design, physical implementation or construction, and finally operation to obsolescence. The architecture aims to be a relatively simple framework upon which all the functions and activities involved in the aforementioned phases of the life of the enterprise-integration project can be mapped. It also will permit the tools used by the investigators or practitioners at each phase to be indicated. The architecture defined will apply to projects, products, and processes; as well as to enterprises.

History

Generalised Enterprise Reference Architecture and Methodology was developed in the 1990s by an IFAC/IFIP Task Force on Architectures for Enterprise Integration, which consisted of Peter Bernus, James G. Nell and others. The IFAC/IFIP Task Force on Architectures for Enterprise Integration was established in 1990 and has studied enterprise-reference architectures ever since.
The task force established the requirements to be satisfied by candidate enterprise-reference architectures and their associated methodologies to fulfill the needs of industry for such aids to enterprise integration. The result has been called GERAM, for "Generalized Enterprise-Reference Architecture and Methodology", by the Task Force. The Task Force has shown that such an architecture is feasible and that several architectures presently available in the literature can already or potentially can fulfill such requirements.
The development of enterprise-reference architecture has evolved from the development of Design Methodology for Advanced Manufacturing Systems in the 1980s, such as CIMOSA, the Open System Architecture for CIM. The GERAM framework was first published by Peter Bernus and Laszlo Nemes in 1994.

Topics

Components

The eight main components, as shown in figure 1 are:
  • Generic Enterprise Reference Architecture : Defines the enterprise related generic concepts recommended for use in enterprise integration projects. These concepts include enterprise systems life cycle; business process modeling; modeling languages for different users of the architecture ; integrated model representation in different model views.
  • Generic Enterprise Engineering Methodologies : Describe the generic processes of enterprise integration. These methodologies may be described in terms of process models with detailed instruction for each step of the integration process.
  • Generic Enterprise Modeling Languages : Define the generic constructs for enterprise modeling adapted to the different needs of people creating and using enterprise models.
  • Generic Enterprise Modeling Tools : Define the generic implementation of enterprise-integration methodologies and modeling languages and other support for creation and use of enterprise models.
  • Enterprise Models : Represents the enterprise operation. These models will be represented using generic modeling language constructs.
  • Ontological Theories : Formalise the most generic aspects of enterprise-related concepts in terms of essential properties and axioms.
  • Generic Enterprise Models : Identify reference models which capture concepts common to many enterprises. GEMs will be used in enterprise modeling to increase modeling process efficiency.
  • Generic Modules : Identify generally applicable products to be employed in enterprise integration.

    Life-Cycle Concept

Provides for the identification of the life-cycle phases for any enterprise entity from entity conception to its final end. The Figure 2: GERA Life-Cycle Concept, shows the GERA life cycle phases of enterprise entities. A total of 9 life cycle phases has been defined.
  • Identification phase allows the identification of the enterprise business or any part of it in terms of its relation to both its internal and external environment. This includes the definition general commitments of the integration or engineering activities to be carried out in relevant projects.
  • Concept phase provides for the presentation of the management visions, missions, values, operational concepts, policies, plus others.
  • Requirement phase allows the description of operational processes and collection of all their functional, behavioural, informational and capability requirements.
  • Design phase is the specification of operational system with all its components satisfying the above requirements. Process and resources alternatives may be specified which provide operational alternatives to be used during the operation.
  • Implementation phase describes the real operational system which may deviate from the designed system due to enterprise preferences or availability of components.
  • Build phase supports the system manifestation, physical implementation of resources, testing and validation for the designed processes and the subsequent release for operation.
  • Operation phase employs the released operational processes and the provided resources to support the life cycle phases of the enterprise products.
  • System Change/Re-Engineering phase allows to modify or re-engineer the operational processes according to newly identified needs or capabilities provided by new technologies.
  • End of Life phase supports the recycling or disposal of the operational system at the ending of its use in the enterprise operation. This phase has to provide concepts for recycling and/or disposal of all or part of the system.

    Enterprise Entity Type Concept

Identifies entity types to be used in enterprise engineering and enterprise integration. Adopting a recursive view of integration altogether five entity types with their associated life-cycles can be identified. The recursiveness of the first four entity types can be demonstrated by identifying the role of the different entities, their products and the relations between them. Figure 3: GERA Enterprise Entity Concept, shows the GERA life cycle phases of enterprise entities. A total of 9 life cycle phases has been defined.
  • Strategic Enterprise Management Entity : defines the necessity and the starting of any enterprise engineering effort.
  • Enterprise Engineering/Integration Entity : provides the means to carry out the enterprise entity type 1. It employs methodologies to define, design, implement and build the operation of the enterprise entity.
  • Enterprise Entity : is the result of the operation of entity type 2. It uses methodologies and the operational system provided by entity type 2 to define, design, implement and build the products of the enterprise.
  • Product Entity : is the result of the operation of entity type 3. It represents all products of the enterprise.
  • Methodology Entity : represents the methodology to be employed in any enterprise entity type.
Figure 3 represents the chain of enterprise entity developments. The type 1 entity will always start creation of any lower level entity by identifying goal, scope and objectives for the particular entity. Development and implementation of a new enterprise entity will then be done by a type 2 entity; whereas a type 3 entity will be responsible for developing and manufacturing a new product. With the possible exception of the type 1 entity all enterprise entities will have an associated entity-life cycle. However, it is always the operational phase of the entity-life cycle in which the lower entity is defined, created, developed and built. The operation itself is supported by an associated methodology for enterprise engineering, enterprise operation, product development and production support
Figure 3 also shows the life cycle of the methodology and the process model developed during the early life cycle phases of the methodology. However, there must be a clear distinction between the life cycle of the methodology with its different phases and its process model. The latter is used to support the operational phase of a particular enterprise entity. The operational relations of the different entity types are also shown in Figure 4: GERA Enterprise Entity Concept, which demonstrates the contributions of the different entities to the type 3 entity life-cycle phases. The manufacturing entity itself produces the enterprise product in the course of its operation phase.