MODAF Concepts
What is the MODAF Ontology?
For a explanation of the fundamentals of Ontology, refer to the article What is an Ontology ?
Although the MODAF Meta Model describes generic types of architectural information and their relationships, if re-use and integration of Architectural Products is required, those Products must also utilise a common Terminology and library of standard elements across architectures. The MODAF Ontology serves this purpose and ensures that each instance of an Architectural Element (e.g. organisation, system, activity, etc) uses a commonly agreed and shared definition for its name.
The purpose of the MODAF Ontology is to provide a standard set of terminology and reference data to support:
- Architectural coherence across the MOD – by ensuring all MODAF users employ the same terminology to describe the elements in their Architectures.
- Architectural comparison – using the same base definitions for standard organisations, systems, activities, etc. allows comparison of different aspects of the business.
- Data exchange clarity – information exchanged between architectural tools can be fully defined using the Ontology.
At the time of publishing the MODAF v1.1 document, the MODAF Ontology was at the feasibility stage. ICAD (Information Coherence Authority for Defence – part of DG Info) is responsible for the MODAF Ontology. The approach being investigated is based on the following premises:
- The BORO Methodology is to be used in developing the Ontology
- The MODAF Ontology will extend the IDEAS model – an AUSCANUKUS effort to develop a common ontology for defence enterprise architecture
- The UK Defence Taxonomy and Thesaurus will be the starting point for development, with inputs from other sources of reference data such as the Defence Data Repository, PLCS, BMS, etc.
A governance regime for the Ontology is yet to be formalised, but will be based on a tiered principle, with IDEAS at the top and individual architectures’ AV-2s at the bottom:
The thinking behind this is that architects can make local extensions to the ontology with relative freedom provided the extension is made formally in an AV-2 and linked back to the ontology. The upper layers are more strictly governed, however. For example, a change to the IDEAS Foundation would require consensus from the four nations, and a change to the MODAF ontology would go through the appropriate MOD information management body (e.g. ICAD). These ideas are not set in stone, and readers are welcome to make suggestions about how to manage the ontology.
It is in the nature of architectures that they tend to reference each other and use common elements. If an architect introduces a new element – e.g. a new system – then it is likely that other architecture will want to reference it. For this reason, there needs to be a way to migrate elements up the tiers as time goes by – one could even foresee this happening at the national level, where more than one nation adopts a new technology or way of working.
The approach being taken in IDEAS allows multiple names (with context) to be applied to all the elements. In other words, elements are created once, but may be named several times by different stakeholders. This mechanism allows communities, nations, etc. to work with their favoured terminology, but still allows for commonality between the parties.
The IDEAS model is still in development, but a first draft should be published mid-2007. In the mean-time, some early parts of the IDEAS Foundation have been presented in public and can be reproduced on this site (with the caveat that they may change before publication):
The Key Elements of the IDEAS Foundation
The suite of MODAF documents on this web site also includes a glossary and acronym list. Whilst these will be consistent with the Ontology, their purpose is only to support the readability of the MODAF documents themselves.
Page version 1.1, dated 4th April 2007