G.M. Nijssen

G.M. Nijssen

Gerardus Maria (Sjir) Nijssen (1937) is a Dutch computer scientist, who was fulltime professor at the University of Queensland. Nijssen is considered the founder of verbalization in computer science, and one of the founders of business modeling and information analysis based on natural language.


Sjir Nijssen finished his study at the Eindhoven University of Technology in 1965, and started working at the Control Data Corporation, a pioneer in the field of computer science, at the European headquarters in Brussels in Belgium. At Control Data early 1970’s Nijssen started with fact-based modeling and developed NIAM, a fact based business practice and notation, was conceived. During this time, he was also associated with several academic institutions and international standards organizations. He has served as Chairman of IFIP WG 2.6 (Databases), member of WG 8.1 (Information Systems) and member of ISO TC97/SC5/WG3 (Conceptual Schema).

During the period of 1982 to 1989 Nijssen was a fulltime professor at the University of Queensland in Brisbane, Australia, where he worked together with Terry Halpin amongst others in further developing NIAM and (Object Role Modeling (ORM). When returning to the Netherlands in 1989, he founded PNA Group, which stands for Professor Nijssen Associates, and accepted a position at the University of Maastricht, Netherlands. After several years, he focused entirely on PNA Group, a company exclusively dedicated to business requirements. He is currently CTO and a member of the Board of Directors of PNA Group. His son Maurice Nijssen has taken over as CEO at PNA Group in 2002. Nijssen has a monthly article in the Business Rules Journal , co-chair of the Object Role Modeling (ORM) conferences, and a member of the OMG SBVR 1.1 Revision Task Force (RTF).


Since 35 years Nijssen's main mission is to develop methods to map and transfer knowledge in a clear way. This knowledge, once stored in a proper knowledge base, can be used consistently and in multiple productive and useful ways. Nijssen is the spiritual father of Natural language Information Analysis Method (NIAM) and via Universal Informatics (UI) and UK to the so called "Cognition enhanced Natural language Information Analysis Method" (CogNIAM), which is a part of the SBVR standard of the Object Role Modeling (OMG).


The Natural language Information Analysis Method (NIAM) is a methodology that was initially developed by G. M. Nijssen in the Netherlands (Europe) in the mid-1970s, and later at the University of Queensland, Australia in the 1980s. The acronym NIAM originally stood for "Nijssen's Information Analysis Methodology", and later generalised to "Natural language Information Analysis Methodology" and Binary Relationship Modeling since Nijssen was only one of many people involved in the development of the method. The Object role modeling evolved from NIAM. Nijssen and Terry Halpin provided the first formalization of Object-Role Modeling in joint papers and the work, Conceptual Schema and Relational Database Design.

Object Role Modeling

Object Role Modeling is a fact-oriented method for performing information analysis at the conceptual level. The quality of a database application depends critically on its design. To help ensure correctness, clarity, adaptability and productivity, information systems are best specified first at the conceptual level, using concepts and language that people can readily understand. The conceptual design may include data, process and behavioral perspectives, and the actual DBMS used to implement the design might be based on one of many logical data models (relational, hierarchic, network, object-oriented etc.).

Universal Informatics

In the 1990s Nijssen developed a seven document architecture for describing organisational processes, also known as Universal Informatics (UI). This is based on three points of view and 7 documents. These three points of view are:

  • Information point of view,
  • Process point of view, and
  • Event/impulse point of view.

Within these three points of views seven documents are created: Three documents for information point of view, three for the process point of view and one last for the Event/Impulse view. Nijssen provided the following descriptions for these documents:

  • Information Base: A set of elementary declarative sentence instances
  • Information Grammar: Prescribes all the permitted states and transitions of the information base; Sentence Types, Constraints and Derivation Rules
  • Information Meta Grammar: Sentence Types, Constraints and Derivation Rules of Information Grammar
  • Process Description: The addition, deletion or selection of fact instances from the Information Base
  • Process Grammar: Defines the permitted populations and transitions of the Process Description
  • Event Description: Under which conditions is a process to be started?
  • Event Grammar: Defines the permitted populations and transitions of the Event Description

Information is the foundation of the seven document architecture. The process and event views are based on information. Within the architecture grammar is described at type level and description/base is provided at the instance level.


Cognition enhanced Natural language Information Analysis Method (CogNIAM) strives to effectively involve users and customers in the business modeling and designing process. This involvement can be achieved by using a small but exact subset of natural language as a means of communication and defining business rules and information system specifications. The use of the natural language subset and associated CogNIAM methodology means understandability for all stakeholders and unambiguous communication between these stakeholders. This is the main basis for the success of PNA and CogNIAM.


BPMN is a graphical modelling language based on CogNIAM and combined with SBVR. The combination of BPMN and SBVR provides a language to undertake the challenge to specify the structure and processes of Business Engineering. In an 2007 issue of the 'Semantics for Business', Sjir Nijssen shares how the Business Engineering Community has started to describe the contributing silos such that the result is an integrative Business Engineering discipline.


Nijssen published more than 50 articles and 7 books.

  • 1976. Modelling in data base management systems: Proceedings of the IFIP Working Conference on Modelling in Data Base Management Systems. Elsevier/North-Holland.
  • 1979. Data Base Architecture. With G. Bracchi. Elsevier.
  • 1984. Introduction to IBM SQL: Covering SQL/DS Release 2. United Enterprises.
  • 1986. SQL: A textbook for Queensland secondary schools. Faith International.
  • 1989. Conceptual Schema and Relational Database Design: A Fact Oriented Approach. With Terry Halpin. Prentice Hall.


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