Proposal for the Subdivision of Project 7.19
for a Petri Net Standard
Contribution to ISO/IEC JTC1/SC7/WG11 SEDDR
Date: 14 August 1995
Subject: Subdivision of Project 7.19 for a Petri net standard
Work Item: 7.19 Diagrams for Software Engineering
Project 7.19.xx Petri Net Standard
The development of an international Petri net Standard has been discussed
in ISO/IEC JTC1/SC7/WG11 at its meetings in Ottawa (June 94), Bonn
(November 94) and Brisbane (June 95). At its meeting in Brisbane, WG11
agreed to the subdivision of Project 7.19 as the appropriate project for
the proposed standard. WG11 submitted a subdivision proposal to the SC7
Plenary, but withdrew it as it was felt that the proposal should be more
The purpose of this contribution is to seek National member body comment on
this proposal, in order to proceed with a subdivision.
Petri net Techniques
2. Scope and Field of Application:
The scope of this subproject is the definition and standardization of a
Petri net technique including graphical notation, syntax and semantics.
Notions of high-level nets and augmentation with time for performance
evaluation are within the scope of this project as are techniques for the
analysis of Petri nets and the development of a transfer syntax.
The technique can be applied to a wide variety of concurrent systems, in
particular distributed systems. The fields of application include
- Development of specifications and designs
- Descriptions of existing systems prior to re-engineering
- Modelling of the software process
- Simulation of systems to increase confidence
- Formal analysis for safety critical systems
3. Purpose and Justification:
Petri nets are a technique for the specification and description of the
dynamic behaviour of systems and in particular those systems that express
the concurrent operation of various subparts. The technique has an
intuitively appealing graphical form, which facilitates understanding of
the behaviour of systems by humans.
Since their invention in the early 1960's, substantial development of the
techniques for the modelling, specification, analysis and testing of a
broad range of systems has occurred over the last 15 years. This has
included extensions for performance analysis (Stochastic Petri nets, Timed
Petri nets) and for concise representations (High-level nets, which include
Nets have been applied to a broad range of systems, particularly those
that may be implemented in software, including operating systems,
databases, communication protocols, manufacturing systems, defence
command and control, business processes and telecommunications. They
have been used in both government and business organisations in a large
number of countries, on six continents. Examples include: specifying
telecommunications services (Deutsche Telekom, Germany); modelling
industrial systems (HP, USA); Multimedia services (LAAS, France);
Application to Railway traffic control (Netherlands); modelling
communication protocols (Telecom Australia); Communication software
development (Oki Electric, Japan); Petri net tool development (Denmark);
Flexible Manufacturing Systems (Spain, France); Large scale document storage
(CIT,Germany); Object orientation (Italy); railway signalling (Australia);
Claims Processing (Meta Software, USA); Production Line
Control (Kobe Steel, Japan); Protocol testing (GMD, Germany); space
communications (ESA, France); safety critical systems (PARSE project,
UK); computer performance modelling (Hitachi, Japan); business
modelling (DMR, CRIM, Canada); dependability and reliability (USA);
protocol performance (South Africa, France); computer supported
co-operative work (Italy); distributed systems (Finland); and banking
(USA) to name a few.
There is an annual Petri net Conference held at the end of June (the next
in June 1996 will be held in Osaka, Japan) and a biennial workshop on Petri
nets and Performance Models, which started in 1985. There is a Petri net
mailing list on the internet (PetriNet-request at daimi dot aau dot dk) and also a
world-wide web page (http://www.daimi.aau.dk/PetriNets/).
In order to develop industrial applications, tool sets for Petri nets are
essential and include: graphical creation and editing; simulation;
functional analysis; performance analysis; testing and automatic
implementation (compilers). There are now a number of commercial tools
available (eg Eval from Verilog, France; Design/CPN from Meta Software, USA;
and PROMPT from Unico Computer Systems, Australia), as well as a large list
of tools from research organisations. A list of these tools is kept on
line by the Canadian organisation CRIM, which can be accessed via the world
3.2 Specific Aims
During their development, many different variants of Petri nets and their
extensions have occurred. The purpose of the standard will be to provide a
reference definition that can be used both within and between
organisations, to ensure a common understanding of the technique, and the
specifications written using the technique. This will allow the standard to
be referenced in contracts, facilitating international enterprize and
trade. It will also facilitate the development and interoperability of
Petri net computer support tools.
The main beneficiaries will be in many industrial sectors, including
telecommunications, defence, aerospace, banking, computing and
transportation. Petri nets can also be used in understanding business
processes and in their re-engineering and this will effect many secondary
and tertiary industries including government service organisations.
A Petri net standard would facilitate the exchange of specifications and
designs written in Petri nets across national boundaries, thus assisting
It would also facilitate the development of compatible tool sets.
The development of the standard is technically feasible. The techniques are
quite mature with several text books available in a number of different
There has now been over 30 years of development of the techniques from
research ideas to a level of maturity necessary for industry uptake. This
has been happening over the last 5 years. In order to facilitate:
understanding of Petri net specifications and designs between suppliers and
clients; and the development of compatible tools, the time is now right to
produce a Petri net standard that is useable by industry.
Numbers of Petri net tools are being produced, most of which are
incompatible. In order to facilitate the electronic exchange of designs and
specifications in Petri net form, it is important that the standard is
produced quickly. The schedule for the standard is given in the Programme
The benefits of a Petri net standard are many including:
- The use of the standard in contracts between purchasers and
suppliers, and between suppliers and their subcontractors. This will allow
unambiguous specifications to be made which are independent of the language
and culture of different countries.
- Use of the standard will allow much better understanding of the
behaviour of the desired systems, by allowing visualisation of both flow of
control and flow of data within a system.
- It will allow specifications and designs in Petri nets to be
transferred between Petri net tools designed and developed by different
- It will allow the development of standard analysis techniques, to
ensure certain properties of systems are captured by the specifications.
- It will allow standard Petri net building blocks to be developed
- It will facilitate debugging of specifications and designs at the
earliest opportunity, before implementation, thus saving costs, and
increasing quality of products and services.
- Facilitating tool support for rapid specification prototyping.
- Facilitation of a market for Petri net tools.
4. Program of Work:
A draft outline of a Working Draft for the standard was produced at the
last SC7/WG11 meeting in Brisbane in June 95 (ISO/IEC SC7/WG11 N182). This
draft is currently being filled out by work in both Australia and Germany.
It will be circulated with this document.
The following schedule is proposed.
Project Working Draft Committee Draft DIS IS
7.19.xx 96-05 97-05 98-05 98-12
The following resources have already been committed in 4 countries.
Denmark Work on Transfer syntax
Germany General contribution to Petri net standard
USA General contribution to Petri net standard
Other resources are expected from many other countries for reviewing the
standard, once the activity is advertised more widely.
5. Reference Documents:
- J. L. Peterson, ``Petri Net Theory and the Modeling of Systems",
Prentice-Hall, N.J., 1981.
- W. Reisig, ``Petri Nets, An Introduction", EATCS, Monographs on
Theoretical Computer Science, W.Brauer, G. Rozenberg, A. Salomaa (Eds.),
Springer Verlag, Berlin, 1985
- K. Jensen, ``Coloured Petri Nets'', Volume 1: Basic Concepts,
- K. Jensen, ``Coloured Petri Nets'', Volume 2: Analysis Methods,
- J. Desel and J. Esparza, ``Free Choice Petri Nets'', Cambridge
Tracts in Theoretical Computer Science 40, Cambridge University Press, 1995
- R. David and H. Alla, ``Petri nets and Grafcet'', Prentice Hall, 1992.
- A. A. Desrochers and R.Y. Al'Jaar, ``Applications of Petri nets in
Manufacturing Systems: Modelling, Control and Performance Analysis'', IEEE
- Advanced Course on Petri Nets, Bad Honnef, West Germany, September
1986. Published in `Advances' series, LNCS Vols 254, 255, 1987.
- E. Best and C. Fernandez, ``Notations and Terminology on Petri Net
Theory'', Arbeitspapiere der GMD 195, March 1987.
- J. Billington, `'Many-sorted High-level Nets", in K. Jensen, G.
Rozenberg (Eds.), High-Level Petri Nets: Theory and Application,
6. Cooperation and Liaison:
Co-operation with the Steering Committee for the International Conferences
on the Application and Theory of Petri Nets. Potential liaison with
ISO/IEC JTC1/SC7/WG9 and IEC TC56 Dependability Aspects of Software.
7. Preparatory Work
7.1 Project Editor:
Australia offers to provide the project editor:
Professor Jonathan Billington
University of South Australia, Australia
Fax +61 8 8302 3873
ph: +61 8 8302 3940
email: <<j dot billington at unisa dot edu dot au>
7.2 Work on Standard.
Canada, Germany, Japan, USA and Australia have provided input to the
Standard during WG11 meetings. Denmark has also committed resources to
working on the standard (see section 4.3).