![]() |
![]() |
Planning Initiative Shared Planning and Activity Representation - SPAR |
Title: Roots of SPAR - Shared Planning and Activity Representation
Author: Austin Tate, AIAI, University of Edinburgh
Date: 17-Nov-97
Abstract
The Defense Advanced Research Projects Agency (DARPA) and US Air Force
Research Laboratory Planning Initiative (ARPI) has initiated a project to
draw on the range of previous work in planning and activity ontologies
to create a practically useful "Shared Planning and Activity
Representation" - SPAR - for use in technology and applications
projects within their communities.
This article describes the previous work which has been used to create the initial SPAR representation. Key examples of the work drawn upon are published in the Knowledge Engineering Review Special Issue on Ontologies [Uschold & Tate, 1998]. The paper provides a comprehensive bibliography and related world wide web resources for work in the area of plan, process and activity representation.
SPAR is now being subjected to refinement during several review cycles by
a number of expert and user panels.
Aims for SPAR
It is important that information about processes, plans and activities
are sharable within and across organisations. Cooperation and
coordination of the planning, monitoring and workflows of the
organisations can be assisted by having a clear shared model of what
comprises plans, processes and activities. The Shared Planning and
Activity Representation (SPAR) is intended to contribute to a range of
purposes including domain modelling, plan generation, plan analysis,
plan case capture, plan communication, behaviour modelling, etc. By
having a shared model of what constitutes a plan, process or activity,
organisational knowledge can be harnessed and used effectively.
The design of SPAR provides structure where there is a consensus on the key entities and relationships amongst those creating and using planning and activity representations. It specifies the structure to a level of detail judged to relate to the needs of the majority of potential users of the representation. However, planning and activity representations are the subject of active research. Some of the current approaches are conceptually simpler or more uniform than SPAR is intended to be - e.g., using pure logic or all constraint [Joslin, 1996; Tate, 1996a] bases. Even where the structure of SPAR itself is not suitable as a basis for novel research or applications, the intention is that the semantics of the SPAR Representation should be clearly defined such that it can be translated to alternative representations. This also provides the important capability that SPAR-represented information will be able to be communicated to future representational frameworks as and when those are adopted in a widespread way.
Scope
The principal scope of SPAR is to represent past, present and possible
future activity and the command, planning and control processes that
create and execute plans meant to guide or constrain future activity.
It can be used descriptively for past and present activity and
prescriptively for possible future activity.
Within the SPAR structure it is possible to specialise the representation through the provision of application, domain or technology specific extensions via Plug-in Ontologies or Grammars with their associated Lexicons of the terms used. This is the level at which current and novel representations of activity and the constraints on activity will be attached. The plug in ontologies or grammars may draw on standard representations being adopted in the AI planning research community such as PDDL [McDermott et. al., 1997] or more constrained grammars may be specified for practical use in today's applications.
Where further shared structure can be agreed in future within a sufficiently broad community, it could be included in a future revision of SPAR. Where more limited communities representing vendors, specific sector users or research interest groups agree on a shared representation, it may be possible to create an extension used within that community using a mechanism such as the PIF "Partially Shared Views" (PSVs) [Lee & Malone, 1990].
Any practical use of a planning and activity representation naturally will relate to more detailed models of the objects involved or the organisational relationships between the people or agents included. It is not intended that SPAR itself prescribes structure for detailed object models or for detailed organisation or agent relationship models. SPAR can co-exist with one or more such models which can therefore be chosen to reflect standards established elsewhere. An example of a detailed object description standard is that established by International Standards Organisation's STEP [ISO, 1995] or EXPRESS [Express, 1995] for product interchange in manufacturing. Examples of organisational and agent relationships models can be found in the Enterprise Models [Fraser & Tate, 1995; Fox et. al., 1993] and the ORDIT Organisational Model [Blyth et. al., 1993].
SPAR may be expressed or represented in a wide variety of ways. It is intended that reference designs and implementations for a number of those which will be mostly commonly useful will be provided. KIF [Genesereth & Fikes, 1992], CommonKADS Conceptual Modelling Language [Schreiber et. al., 1994], Conceptual Graphs [Sowa, 1984], LOOM [Brill, 1993], CDIF [Ernst, 1997] or other representations of SPAR are possible.
History
The AI planning community has used explicit domain description
languages and plan definitions for more than 25 years [Tate et. al., 1990; Allen
et. al., 1990]. As long ago as the late 1960s, work on the STRIPS
operator representation of actions [Fikes &
Nilsson, 1971] was used to practical effect for planning and
control of the SRI Shakey robot. This early application was based
upon more theoretical roots in the QA3 theorem prover [Green, 1969] and situation calculus [McCarthy & Hayes, 1969]. There is now a
wealth of experience of defining plan representations from both
theoretical studies and practical planning.
In 1992, under the DARPA/Air Force Research Laboratory (Rome) Planning
Initiative (ARPI) [Fowler et. al., 1995], a
number of participants created the KRSL plan language [Lehrer, 1993]. Although this has been used for
some transfers of information between planning components within the
ARPI (in particular an Integrated Feasibility Demonstration called
IFD-2 [Burstein et. al., 1995]), it has not
had the widespread impact desired. Its structure was too rigid and
KRSL excluded much that was already being done within AI planning
research. However, it did establish a range of entities which needed
to be in a plan representation and was an influence on subsequent
work.
In 1994, a group was formed to create an ontology for plans, using new insights gained over the last few years in the knowledge-sharing community in the US [Neches et. al., 1991; Genesereth & Fikes, 1992; Gruber, 1993] and Europe [Uschold, 1998; Breuker & van de Velde, 1994]. This led to an outline plan model called KRSL-Plans [Tate, 1996b]. However, this work was not brought to a conclusion though it did feed into subsequent work.
Since 1995, there have been a number of initiatives to standardise terminology in the subject area of activities and plans. These include enterprise processes in PIF (the Process Interchange Format [Lee et. al., 1996]); workflow (International Workflow Management Coalition [WfMC, 1994]); CASE systems data modelling exchange in CDIF [Ernst, 1997; Navarro, 1996]; manufacturing processes (NIST's Process Specification Language [Schlenoff et. al., 1996]); and the Object Model Working Group's CPR (Core Plan Representation - [Pease & Carrico, 1997]). These initiatives have involved academic, government and industry participants.
In the US military planning research community and beyond, there has been work to use verb/noun phrase grammars to represent plan objectives and activities [Valente et al., 1996; Hess, 1996; Kingston et. al., 1997; Drabble et. al., 1997].
In August 1997, DARPA and the Air Force Research Laboratory (Rome) Programme Managers for ARPI proposed a renewed effort to tap into this accumulated expertise, and to create a shared plan representation suitable for practical use in ARPI and on applied research programmes in their communities. The representation is expected to be considerably more detailed than the more conceptual ontology efforts which have gone before it.
SPAR is drawing on this wide range of previous work.
Plan ontologies and representations created by participants of ARPI-related projects include:
Since 1994, work within ARPI on plan representations has proceeded in parallel with pre-standards work on process interchange and representation. ARPI researchers have been involved in these activities, and others have supported the continuing ARPI work - including helping in the development and review of SPAR. The relevant standards activities that have been jointly pursued are:
A common model of processes and activity has emerged from this work and has been used as the basis for the initial version of SPAR.
Development, Refinement and Review Process
SPAR is being developed in the following way:
SPAR Model
A set of statements called the KRSL-Plans description (version dated
20-Sep-96) was used as a starting point for the SPAR model of planning
and activity. These were created by the Plan Ontology Construction
Group within ARPI. These statements were a refinement of an earlier
version dated 2-Feb-95 (published in [Tate, 1996b]). The later version of these statements
was also used to provide ARPI participants input to the development of
OMWG's Core Plan Representation (CPR). [square brackets are used to
indicate phases or options that were not fully agreed]. The top level
statements are:
Then at a second level of detail, the statements are:
The model is expected to develop from this base.
Status
A project has been started within the ARPI community to develop a
Shared Planning and Activity Representation - SPAR - for practical use
in technology and applications projects within US government research
and development communities and beyond.
An initial version of SPAR has been produced utilising the wide range of previous work on plan, process and activity ontologies and representations. This is being subjected to review and refinement through a number of Request For Comment documents involving technical specialists and application-oriented user panels. Following these reviews, the intention is to publish a first version in mid 1998 and then to collect experience in the application of the representation.
It is intended that a process for sharing experiences of using SPAR will be established and continuing design issues tracked. A collected volume of papers describing SPAR and relating experience in using, adapting or extending the representation is planned in the medium term.
Acknowledgements
This work is sponsored by the Defense Advanced Research Projects
Agency (DARPA) and the Air Force Research Laboratory (Rome), Air Force
Materiel Command, USAF, under grant numbers F30602-95-1-0022 and
F30602-97-C-0275. The US Government is authorised to reproduce and
distribute reprints for Governmental purposes notwithstanding any
copyright annotation hereon. The views and conclusions contained
herein are those of the authors and should not be interpreted as
necessarily representing official policies or endorsements, either
express or implied, of DARPA, AFRL, the US Government, members of the
SPAR Core Group or other SPAR participants.
Thanks to the many people who have provided input to the planning, process and activity ontologies which have provided the roots for the work on SPAR and enabled rapid progress to be made in its initial development. Special thanks to Steve Polyak for helping to complete the extensive set of references in this paper. Thanks to Paul Krause, Simon Parsons, Steve Polyak and Mike Uschold for reviewing the text.
Allen, J.F., 1984. "Towards a General Theory of Action and Time" Artificial Intelligence 23 123-154.
Blyth A.J.C., Chudge, J., Dobson, J.E. and Strens, M.R., 1993. "ORDIT: A new methodology to assist in the process of eliciting and modelling organisational requirements" In Proceedings on the Conference on Organisational Computing Systems, November, San Jose, CA, USA. http://www.twente.research.ec.org/esp-syn/text/2301.html
Breuker, J., van de Velde, W., 1994. The CommonKADS Library for Expertise Modelling: Reusable Components for Artificial Problem Solving, IOS Press. http://www.swi.psy.uva.nl/projects/CommonKADS/home.html.
Brill, D., 1993. "LOOM Reference Manual v.2.0", Information Sciences Institute, University of Southern California. http://www.isi.edu/isd/LOOM/LOOM-HOME.html
Burstein, M.H., Schantz, R., Bienkowski, M.A., desJardins, M.E. and Smith, S.F., 1995. "The Common Prototyping Environment -- A Framework for Software Technology Integration, Evaluation and Transition" IEEE Expert 10(1) February 17-26, IEEE Comp. Soc. http://arpi.isx.com
Drabble, B., Lydiard, T. and Tate, A., 1997. "Process Steps, Process Products and System Capabilities", Artificial Intelligence Applications Institute, University of Edinburgh, Technical Report ISAT-AIAI/TR/4 Version 2, April 14, 1997. http://www.aiai.ed.ac.uk/~arpi/ACP-MODELS/ACP-PROCESS/97-APR/TEX-PS/isat-report4.ps
Ernst, J., 1997. Introduction to CDIF, CASE Data Interchange Format Division Electronic Industries Association. http://www.cdif.org
EXPRESS Information Modelling Language, 1995. ISO WD 10303-11. http://www.eurpc2.demon.co.uk/part11.html
Fowler, N., Cross, S.E. and Owens, C., 1995. "The ARPA-Rome Knowledge-Based Planning and Scheduling Initiative" IEEE Expert, 10(1) February 4-9, IEEE Comp. Soc. http://arpi.isx.com
Fraser, J. and Tate, A., 1995. "The Enterprise Tool Set -- An Open Enterprise Architecture" In Proceedings of the Workshop on Intelligent Manufacturing Systems, International Joint Conference on Artificial Intelligence (IJCAI-95), Montreal, Canada. http://www.aiai.ed.ac.uk/~entprise/enterprise/ontology.html
Fox, M.S., Chionglo, J.F. and Fadel, F.G., 1993. "A Common-Sense Model of the Enterprise" In Proceedings of the Second Industrial Engineers Research Conference (IERC) Norcross, GA, Institute for Industrial Engineers. http://www.ie.utoronto.ca/EIL/tove/toveont.html
Genesereth, M.R. and Fikes, R.E., 1992. "Knowledge Interchange Format, Version 3.0 Reference Manual", Knowledge Systems Laboratory, KSL-92-86. http://ksl-web.stanford.edu/KSL_Abstracts/KSL-92-86.html.
Gruber, T., 1993. "Ontolingua: A Translation Approach to Providing Portable Ontology Specifications" Knowledge Acquisition 5(2) 199-200. http://ksl-web.stanford.edu/KSL_Abstracts/KSL-92-71.html.
ISO, 1995. "Product Data Representation and Exchange: Part 49: Integrated Generic Resources: Process Structure and Properties", ISO Standard 10303-49, International Standards Organization. http://www.nist.gov/sc4/www/stepdocs.htm
Joslin, D., 1996. "Planner/Scheduler Interface Proposal", Draft, CIRL, University of Oregon, 17-May-96. http://www.cirl.uoregon.edu/joslin/Papers/psi.ps.
Khambhampati, S, 1997. "Refinement Planning" AI Magazine, 18(2), pp. 67-97, Summer 1997.
Kingston, J.K., Griffiths, A. and Lydiard, T.J., 1997. "Multi-Perspective Modelling of the Air Campaign Planning Process" In Proceedings of the Fifteenth International Joint Conference on Artificial Intelligence (IJCAI-97), Nagoya, Japan. http://www.aiai.ed.ac.uk/~arpi
Knight, K. and S. Luk., 1994. "Building a Large Knowledge Base for Machine Translation". In Proceedings of the American Association of Artificial Intelligence Conference (AAAI-94), July 31, August 3, 1994, Seattle, WA. http://www.isi.edu/natural-language/resources/sensus.html#pubs
Lee, J. and Malone, T., 1990. "Partially Shared Views: A Scheme for
Communicating between Groups Using Different Type Hierarchies" ACM
Transactions on Information Systems 8(1) 1-26.
Lee, J. (ed.), Gruninger, M., Jin, Y., Malone, T., Tate,
A., Yost. G., and other members of the PIF Working Group, 1996. "Process
Interchange Format and Framework, Version 1.1", MIT Center for
Coordination Science, Working Paper No. 194. http://ccs.mit.edu/pif
Lehrer, N. (ed.), 1993. "ARPI KRSL Reference Manual 2.0.2", ISX
Corporation.
http://isx.com/pub/ARPI/ARPI-pub/krsl/krsl-info.html
McDermott, D., 1997. "PDDL - The Plan Domain Definition Language",
Computer Science, Yale University. http://www.cs.yale.edu/HTML/YALE/CS/HyPlans/mcdermott.html
Moralee, S., 1994. "Notes from Enterprise Project Workshop on Content,
Form and Methods for Ontologies", IBM(UK) Offices, Nottingham, UK,
Dated 25-Nov-94. http://www.aiai.ed.ac.uk/~bat/ontology-may94.html.
Navarro, T., 1996. "CDIF - Integrated Meta-model - Project Management
Planning and Scheduling Subject Area", Report EIA-PN3239,
CDIF-DRAFT-PMPS-V04, CASE Data Interchange Format Division, Electronic
Industries Association. http://www.cdif.org/overview/ProjectManagement.html
Neches, R., Fikes, R., Finin, T., Gruber, T.R., Patil, R., Senator, T. and
Swartout, W.R., 1991. "Enabling Technology for Knowledge Sharing" AI
Magazine 12(3) 36-56. http://ksl-web.stanford.edu/KSL_Abstracts/KSL-93-23.html.
NIST, 1993. "Integrated Definition for Function Modeling (IDEF0)",
Federal Information Processing Standards (FIPS) Publication 183,
National Institute of Standards and Technology, December 21,
1993. http://www.idef.com
Pease, R.A. and Carrico, T.M., 1997. "Object Model Working Group (OMWG)
Core Plan Representation - Request for Comment", version 2, 24 January
1997, Defense Advanced Research Projects Agency. http://www.teknowledge.com/CPR2/
Schlenoff, C. (ed.), Knutilla, A., and Ray, S.,
1996. "Unified Process Specification Language: Functional Requirements
for Modeling Processes", National Institute of Standards and
Technology, Gaithersburg, Maryland. http://www.nist.gov/psl/
Madni, A. and Mi, P., 1997. "IDEON Specification in CORBA
IDL", Technical Memo ISTI-TM-7/97, July 17, 1997, Intelligent Systems
Technology, Inc., Santa Monica, CA. http://www.intelsystech.com
Schreiber, G., Weilinga, B., Akkermans, H. and Van
de Velde, W., 1994. "CML: The CommonKADS Conceptual Modelling Language"
In L. Steels, G. Schreiber and W. Van de Velde (eds.) A future for
knowledge acquisition: Proceedings of EKAW-94, Hoegaarden,
Belgium, Springer-Verlag.
http://www.swi.psy.uva.nl/projects/Kactus/toolkit/cml.html
Smith, S.F. and Becker, M., 1997. "An Ontology for
Constructing Scheduling Systems" In Working Notes from 1997 AAAI
Spring Symposium on Ontological Engineering, Stanford, CA, AAAI
Press. http://www.cs.cmu.edu/afs/cs/project/ozone/www/AAAI_Symp_On_Ontol_97/abstract.html
Swartout, B. and Gil, Y., 1995. "EXPECT: Explicit Representations for
Flexible Acquisition" In Proceedings of the Ninth Knowledge
Acquisition for Knowledge-Based Systems Workshop, February
26-March 3, 1995.
http://www.isi.edu/expect/expect-homepage.html
Tate, A., 1994. "A Plan Ontology - a Working
Document - October 31, 1994" In Proceedings of the Workshop on
Ontology Development and Use, 2nd - 4th November, La Jolle,
CA. ftp://ftp.aiai.ed.ac.uk/pub/documents/1994/94-ont-plan-ontology.ps
Tate, A., 1995. "O-Plan Task Formalism Manual",
Version 2.3, July 12, 1995. Artificial Intelligence Applications
Institute, University of Edinburgh. ftp://ftp.aiai.ed.ac.uk/pub/documents/ANY/oplan-tf-manual.ps
Tate, A., 1996a. "Representing Plans as a Set of
Constraints -- the <I-N-OVA> Model" In Proceedings of the
Third International Conference on Planning Systems (AIPS-96),
Edinburgh, Scotland, May 1996, AAAI Press, pp. 221-228. http://www.aiai.ed.ac.uk/~oplan/inova.html
Tate, A. (ed.), 1996b. "KRSL-Plans", Appendix of
Tate, A, "Towards a Plan Ontology" AI*IA Notizie (Quarterly
Publication of the Associazione Italiana per l'Intelligenza
Artificiale), Special Issue on "Aspects of Planning Research"
9(1), pp. 19-26. A shorter version of [Tate, 1994]. ftp://ftp.aiai.ed.ac.uk/pub/documents/1996/96-aiia-plan-ontology.ps
Tate, A (reporter) and the PIF Working Group,
1996. "PIF and the Workflow Management Coalition WPDL, Report of
Session at the PIF Workshop", Stanford University, 11-Jul-96.
http://ccs.mit.edu/pif
Tate, A., Drabble, B. and Kirby, R.B., 1994. "O-Plan2:
an Open Architecture for Command, Planning and Control" In M. Fox and M.
Zweben (eds.) Intelligent Scheduling, Morgan Kaufmann. http://www.aiai.ed.ac.uk/~oplan/
Uschold, M.F.,
1998. "Concepts and Terminology for Knowledge Sharing" Knowledge
Engineering Review, Special Issue on Ontologies, To appear,
Cambridge University Press. http://www.aiai.ed.ac.uk/~euroknow
Uschold, M.F., Moralee, S., King, M. and
Ziorgios, Y., 1998. "The Enterprise Ontology" Knowledge Engineering
Review, Special Issue on Ontologies, To appear, Cambridge
University Press. http://www.aiai.ed.ac.uk/~entprise/enterprise/ontology.html
Valente, A., Swartout, W. R. and Gil, Y., 1996.
"A Representation and Library for Objectives in Air Campaign
Plans". http://www.isi.edu/expect/inspect.html
Wilkins, D.E., 1988. Practical Planning
Morgan Kaufmann.http://www.ai.sri.com/~sipe
Wilkins, D.E. and Myers, K.L., 1995. "A Common Knowledge
Representation for Plan Generation and Reactive Execution" Journal
of Logic and Computation 5(6) 731-761. http://www.ai.sri.com/~act/act-formalism.html
World Wide Web Consortium, RDF Metadata Format, Draft 3-Oct-97. http://www.w3.org/Press/RDF
Workflow Management Coalition, 1994. "Workflow Management Coalition
Glossary", A Workflow Management Coalition Specification,
November. http://www.wfmc.org
ARPI Home Page | SPAR Home Page |