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DSPL: Design Specialists and Plans Language


Dave Brown et al.


The Design Specialists and Plans Language (DSPL) is a language in which to capture the knowledge of how to produce a design. It is intended for routine design situations. It has been tried on mechanical, electrical and civil engineering tasks. The best-known use for the language was in the AIR-CYL Air Cylinder design system.

Routine design means that everything about the design process, including the knowledge needed, must be known in advance. Note that this does not mean that the specific design (i.e., the solution) is known in advance. Nor does it mean that the pattern of use of the knowledge (i.e., the design trace) is completely known in advance, but portions of it may be.

The language offers the ability to encode knowledge as different types of "agents". Each type plays a specific role (function) in the final design process. As the knowledge represents routine problem-solving then we would expect it to be highly compiled.

Specialists act as place-holders for Plans and plan selection knowledge (Sponsors & Selectors). They each represent a subproblem, solving it by plan selection and execution. Plans are precompiled sequences of actions intended to provide the design for a subproblem. A Plan provides ordering of design activity and a subproblem decomposition. Plans also provide the basis for solution recomposition. A Sponsor evaluates the suitability of a plan for use in a particular situation, while a Selector picks a suitable Plan.

Steps represent the building blocks of the design process, providing a value for an attribute of the design. This is done using calculation or decision, or by selection using pattern matching. Tasks group steps, and therefore help to define the problem decomposition. Constraints test values and make suggestions about patches. Redesigners attempt to patch the design in order to correct a constraint failure. Failure Handlers recognize failing situations that might be patchable, or can trigger backtracking.


D.C. Brown (Aug. 1984) Expert Systems for Design Problem-Solving using Design Refinement with Plan Selection and Redesign, Ph.D. Dissertation, Department of Computer & Information Science, Ohio State University, Columbus, Ohio, USA. Advisor: B. Chandrasekaran.

An edited form of the dissertation, with some additional material, appears as:

D.C. Brown & B. Chandrasekaran (May 1989) Design Problem Solving: Knowledge Structures and Control Strategies. Research Notes in Artificial Intelligence Series, Pitman Publishing, Ltd., London, England. {Published in the US by Morgan Kaufmann}

Also see the DSPL Thesis web page for information, including the original AIR-CYL DSPL.


D.C.Brown & B.Chandrasekaran (May 1983) An Approach to Expert Systems for Mechanical Design, Trends & Applications Conference, IEEE Computer Society, National Bureau of Standards, Gaithersburgh, Maryland, pp. 173-180. {Report on prototype of design system plus research agenda.}

D.C.Brown & B.Chandrasekaran (Aug. 1984) An Expert System for Mechanical Design: a Progress Report, Proc. ASME Computers in Engineering Conference, Las Vegas, Nevada.

D.C.Brown & B.Chandrasekaran (April 1985) Plan Selection in Design Problem-Solving, Proc. AISB'85, Society for the Study of Artificial Intelligence and the Simulation of Behavior, Warwick, England.

D.C.Brown (Aug. 1985) Capturing Mechanical Design Knowledge, Proc. ASME International Computers in Engineering Conference, Boston, Mass.

D.C.Brown & B.Chandrasekaran (Oct. 1985) Expert Systems for a Class of Mechanical Design Activity, Knowledge Engineering in Computer-Aided Design, J.S.Gero (Ed.) North Holland, pp. 259-282.

D.C.Brown (Oct. 1985) A Data-Base for a Design Expert System, Proc. 2nd Annual ACM Northeast Regional Conference, Framingham, Mass.

D.C.Brown (Nov. 1985) Failure Handling in a Design Expert System, Computer-Aided Design, (Ed.) J.S.Gero, Butterworths.

D.C.Brown & R.Breau (April 1986) Types of Constraints in Routine Design Problem-Solving, Proc. 1st Int. Conf. on Applications of AI to Engineering Problems, Southampton University, UK.

D.C.Brown & B.Chandrasekaran (July 1986) Knowledge and Control for a Mechanical Design Expert System, IEEE Computer, Special Issue on Expert Systems for Engineering Problems, (Ed.) Se June Hong.

D.C.Brown & B.Chandrasekaran (Aug 1986) DSPL: a language for constructing routine design systems, Workshop on Knowledge-Based Expert Systems for Engineering Design,, AAAI-86, Fifth National Conference on Artificial Intelligence, University of Pennsylvania, Philadelphia, Penn.

D.C.Brown (Oct. 1986) DSPL. Proc. Workshop on High Level Tools for Knowledge Based Systems, by invitation, sponsored by DARPA, AAAI, OSU-LAIR.

D.Herman & D.C.Brown (1987) DSPL: a Language for Routine Design and Planning. In: The Applied Artificial Intelligence Reporter, Part I, Vol.4, No.4, April; Part II, Vol.4, No.5, May; Part III, Vol.4, No.6, June; Part IV, Vol.4, No.7, July.

D.C.Brown & W.N.Sloan (August 1987) Compilation of Design Knowledge for Routine Design Expert Systems: an Initial View. Proc. ASME Conference on Computers in Engineering, New York, New York.

T.Y.L.Chiang & D.C.Brown (August 1987) DSPL Acquirer: A System for the Acquisition of Routine Design Knowledge. Proc. 2nd International Conference on the Applications of Artificial Intelligence in Engineering, Boston, MA.

A.Kassatly & D.C.Brown (August 1987) Explanation for Routine Design Problem Solving. Proc. 2nd International Conference on the Applications of Artificial Intelligence in Engineering, Boston, MA.

D.C.Brown & B.Chandrasekaran (April 1988) Expert Systems for a Class of Mechanical Design Activity, Expert Systems in Engineering, (Ed.) D.T.Pham, IFS Publications/Springer-Verlag, pp.334-360. Selected Reprint from (Oct. 1985) Knowledge Engineering in Computer-Aided Design, J.S.Gero (Ed.), North Holland, pp. 259-282.

R.Kwauk & D.C.Brown (Aug 1988) Generating and Applying Failure Recovery Suggestions in Hierarchical Design Systems. Artificial Intelligence in Engineering: Diagnosis and Learning, (Ed.) J.Gero, Computational Mechanics Publications, Southampton, UK, pp. 29-50.

W.N.Sloan & D.C.Brown (Aug 1988) A Method of Constraint Compilation in Routine Design Expert Systems. Workshop on AI in Design, AAAI-88, Seventh National Conference on Artificial Intelligence, St. Paul, Minn.

R.Horner & D.C.Brown (July 1990) Knowledge Compilation using Constraint Inheritance. Proc. 5th International Conf. on Applications of AI in Engineering, Boston, MA.

E.W.Large & D.C.Brown (July 1990) Knowledge Compilation by Analogy: Adaptation of Design Plans by Analogical Matching and Derivational Plan Transformation. Proc. 5th International Conf. on Applications of AI in Engineering, Boston, MA.

E.J.Meehan & D.C.Brown (Sept 1990) Constraint Absorption and Relaxation using a Design History. Proc. 2nd ASME International Conference on Design Theory & Methodology, Chicago, IL.

D.C.Brown & M.B.Spillane (June 1991) An Experimental Evaluation of some Design Knowledge Compilation Mechanisms. Artificial Intelligence in Design '91, Proceedings of the 1st International Conference on AI in Design, Edinburgh, Scotland, Butterworth-Heinemann Publishers.

D.C.Brown, R.Horner, M.Kim, E.Large, J.Liu, E.Meehan, W.N.Sloan & M.Spillane (1992) Experiences with Modelling Memory and Simple Learning in Routine Design Problem-Solving Systems. Knowledge Aided Design, (Ed.) M.Green, Academic Press, pp. 239-257.

D.C.Brown & B.Chandrasekaran (1992) Investigating Routine Design Problem Solving. Invited Chapter, AI in Engineering Design, Vol. 1, (Eds.) C.Tong & D.Sriram, Addison-Wesley.

D.C.Brown (June 1992) "The Reusability of DSPL Systems", Workshop on Reusable Design Systems. Second International Conference on AI in Design, Carnegie Mellon University, Pittsburgh, PA.

M.B.Spillane & D.C.Brown (July 1992) Evaluating Design Knowledge Compilation Mechanisms. Intelligent Computer Aided Design, (Eds.) D.C.Brown, M.Waldron & H.Yoshikawa, Elsevier Science Publishers B.V. (North-Holland), pp. 351-373.

R.Chabot & D.C.Brown (Spring 1994) Knowledge Compilation Using Constraint Inheritance. (AI EDAM): Artificial Intelligence in Engineering Design, Analysis and Manufacturing, Special Issue: Machine Learning in Design, (Eds.) M.L.Maher, D.C.Brown, A.H.B.Duffy, Vol.8, No.2, pp. 125-142.

W.F.Punch, A.K.Goel & D.C.Brown (Sept. 1995) A Knowledge-Based Selection Mechanism for Strategic Control with Application in Design, Assembly, and Planning. International Journal of Artificial Intelligence Tools, Vol. 4 (3), pp. 323-348.

DSPL-related Theses:

Amal Kassatly, December 1986. "An Investigation of Explanation for Routine Design Problem-Solving", M.S. Thesis.

Teresa Chiang, April 1987. "A Knowledge Acquisition System for the DSPL Language", M.S. Thesis.

Dr. Bill Sloan, May 1988. "Constraint Adjustment during Knowledge Compilation for Routine Design Problem-Solving", M.S. Thesis.

Reimin Kwauk, August 1988. "A Study of Failure Handling in Routine Design", M.S. Thesis.

Ujjwell Trivedi, September 1988. "An expert system for gear train design", M.S. Thesis.

Edward Large, August 1989. "Analogical Reasoning in Design Knowledge Compilation", M.S. Thesis.

Rosemary Horner, October 1989. "Knowledge Compilation using Constraint Inheritance", M.S. Thesis.

Emad Muntasser, May 1990. "An electronic design expert system", M.S. Thesis.

Edmund Meehan, May 1990. "A Model for Constraint Absorption in Routine Design Knowledge", M.S. Thesis.

Maryann Spillane, November 1990. "Knowledge Compilation for Design Expert Systems: A Performance Evaluation", M.S. Thesis.

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dcb@cs.wpi.edu / Wed Sep 11 21:22:10 EDT 1996