The first Technical Note in this series [1] introduced the international standard ISO 10303, informally known as STEP, and the second [2] dealt with some practical aspects of using the standard for the exchange of CAD models. It was noted in [1] that the current published parts of the standard are restricted to the representation and exchange of non-parameterized models. The present contribution discusses the implications of that restriction and describes the progress of the ISO TC184/SC4 committee towards its removal. As will be shown, this extension of the STEP standard will lead to considerable benefits for industry.

1.
Pratt
,
M. J.
,
2001a
, “
Introduction to ISO 10303—the STEP Standard for Product Data Exchange
,”
ASME J. Comput. Inf. Sci. Eng.
,
1
, No.
1
, pp.
102
103
.
2.
Pratt
,
M. J.
,
2001b
, “
Practical Aspects of using the STEP Standard
,”
ASME J. Comput. Inf. Sci. Eng.
,
1
, No.
2
, pp.
197
199
.
3.
ISO, 1994a, ISO 10303:1994, “Industrial Automation Systems and Integration—Product Data Representation and Exchange,” Geneva, Switzerland: International Organization for Standardization (ISO).
4.
Shah, J. J., and Ma¨ntyla¨, M., 1995, Parametric and Feature-based CAD/CAM, New York: John Wiley & Sons.
5.
ISO, 1998a, ISO 13584:1998, “Industrial Automation Systems and Integration—Parts Library,” Geneva, Switzerland: International Organization for Standardization (ISO).
6.
ISO, 1998b, ISO 13584-20:1998, “Industrial Automation Systems and Integration—Parts Library—Part 20: General Resources: Logical Model of Expressions,” Geneva, Switzerland: International Organization for Standardization (ISO).
7.
Pratt
,
M. J.
, and
Anderson
,
W. D.
,
2001
, “
A Shape Modeling Applications Programming Interface for the STEP Standard
,”
Computer-Aided Design
,
33
, No.
7
, pp.
531
543
.
8.
PDES Inc., 2001, http://pdesinc.aticorp.org
9.
PDES Inc., 1997, “ENGEN Data Model Version 4.6,” SCRA, Charleston, SC.
10.
Anderson, W. D., and Ansaldi S., 1998, “ENGEN Data Model: A Neutral Model to Capture Design Intent,” in G. Jacucci, G. J. Olling, K. Preiss and M. J. Wozny (eds.), CDROM Procs. of IFIP PROLAMAT’98 conference, Trento, Italy, Sept. 1998; Boston: Kluwer Academic Publishers.
11.
ISO, 2001, ISO CD 10303-108, “Industrial Automation Systems and Integration—Product Data Representation and Exchange—Part 108: Integrated Application Resource: Parameterization and Constraints for Explicit Geometric Product Models” (available on the World Wide Web at http://www.nist.gov/sc4/wg-qc/wg12/n940).
12.
ISO, 1994b, ISO 10303-11:1994, “Industrial Automation Systems and Integration—Product Data Representation and Exchange—Part 11: Description Methods: The EXPRESS Language Reference Manual,” Geneva, Switzerland: International Organization for Standardization (ISO).
13.
USPro, 1996, USPRO/IPO-100-1996, “Computer Aided Processing of Engineering Drawings and Related Documentation (IGES Version 5.3),” Charleston, SC: US Product Data Association (US National Standard).
14.
Bettig
,
B.
, and
Shah
,
J. J.
,
2000
, “
Derivation of a Standard Set of Geometric Constraints for Parametric Modeling and Data Exchange
,”
Computer Aided Design
,
33
,
17
33
.
15.
ISO, 2000, ISO TC184/SC4/WG12 N527, “JNC Proposal for STEP Assembly Model for Products” (early working draft of ISO 10303-109, available on the World Wide Web at http://www.nist.gov/sc4/wg-qc/wg12/n527).
16.
ISO, 1997, ISO 10303-47:1997, “Industrial Automation Systems and Integration—Product data Representation and Exchange—Part 47: Integrated Generic Resources: Shape Variation Tolerances,” Geneva, Switzerland: International Organization for Standardization (ISO).
17.
ISO, 1999, Technical Specification TS 17450:1999, “Geometrical Product Specifications (GPS)—Model for Geometric Specification and Verification,” Geneva, Switzerland: International Organization for Standardization (ISO).
18.
ASME, 1994a, ASME Y14.5M-1994, “Dimensioning and Tolerancing,” New York: American Society of Mechanical Engineers (US National Standard).
19.
ASME, 1994b, ASME Y14.5.1M-1994, “Mathematical Definition of Dimensioning and Tolerancing Principles,” New York: American Society of Mechanical Engineers (US National Standard).
20.
Srinivasan
,
V.
,
1999
, “
A Geometrical Product Specification Language Based on a Classification of Symmetry Groups
,”
Computer Aided Design
,
31
, No.
11
, pp.
659
668
.
21.
Capoyleas
,
V.
,
Chen
,
X.
, and
Hoffmann
,
C. M.
,
1996
, “
Generic Naming in Generative Constraint-based Design
,”
Computer Aided Design
,
28
, No.
1
, pp.
17
26
.
22.
Kripac, J., 1995, “A Mechanism for Persistently Naming Topological Entities in History-based Parametric Solid Models,” in C. M. Hoffmann and J. R. Rossignac (eds.), Proc. 3rd ACM Symposium on Solid Modeling and Applications, Salt Lake City, UT, 17–19 May 1995; New York, ACM Press.
23.
Raghothama
,
S.
, and
Shapiro
,
V.
,
1998
, “
Boundary Representation Deformation in Parametric Solid Modeling
,”
ACM Trans. Computer Graphics
,
17
, No.
4
, pp.
259
286
.
You do not currently have access to this content.