Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Validating STEP Application Models at the National PDES Testbed



KC Morris, Mary Mitchell, David A. Sauder


This document is part of the National PDES Testbed Report Series and is intended to complement the other reports of the Validations Testing Systems (VTS) project. Other documents are available which fully described the validation methodology used in the Testbed, software requirements for the VTS, and details of the software which automates that methodology. These are referred to throughout this report.

The problem of sharing data has many facets. The need for the capability to share data across multiple enterprises, different hardware platforms, different data-storage paradigms and systems, and a variety of network architectures is growing. The emerging STandard for the Exchange of Product model data (STEP), a project of the International Organization for Standardization (ISO), addresses this need by providing information models, called Application Protocols, which clearly and unambiguously describe data. Application protocols address the data sharing needs for a particular application area and the integration of that information with other application areas through STEP. The validity of these application protocols is essential for success in sharing-data in a highly automated environment.

This document describes how application models within STEP Application Protocols will be validated in the National PDES Testbed at the National Institute of Standards and Technology. (PDES, Product Data Exchange using STEP, is the U.S. effort in support of the international standard.) Application Protocol development and testing is a complex process which involves synthesizing, analyzing, and manipulating large amounts of diverse information. Most of the process relies exclusively on human capabilities for analysis, judgment, and interaction; however, part of this process can and should be automated. A strategy for automation is based on an analysis of the information flow needed for the development and testing process and initial experiences with automation for validation testing at the PDES Testbed.

NIST Interagency/Internal Report (NISTIR) - 4735
Report Number


PDES, product model, software, STEP, Validations Testing Systems (VTS)


Morris, K. , Mitchell, M. and Sauder, D. (1991), Validating STEP Application Models at the National PDES Testbed, NIST Interagency/Internal Report (NISTIR), National Institute of Standards and Technology, Gaithersburg, MD, [online],, (Accessed May 23, 2024)


If you have any questions about this publication or are having problems accessing it, please contact

Created December 31, 1990, Updated October 12, 2021