Dr. David Loffredo
Vice President of Product Development

Dr. David Loffredo is a co-founder of STEP Tools, Inc. and Vice President of Product Development. He has led eighteen major releases of the STEP Tools software, now in over a million CAD seats and manufacturing over a million aerospace parts in 2019. Since 1988, he has developed core engineering software for managing ISO 10303 STEP CAD and IFC BIM data, CNC machining with STEP-NC, and Digital Twin for manufacturing.

Editor of the AP-238 STEP-NC ISO standard, project leader for the STEP file exchange format, and convener of ISO TC184/SC4 Working Group 11, which handles the STEP file formats, information modeling languages, and programming language bindings.

Principal investigator for the National Simulation Service DARPA Phase I & II SBIR (2010-2016), which drove STEP Tools digital twin engine, and Principal investigator for the Web Smart Modeling Environment Navy Phase II SBIR (2001-2003), which adapted STEP-NC for CNC plate cutting for shipbuilding.

He has authored technical papers, articles, and training courses on EXPRESS information modeling, the STEP, STEP-NC, and CIS/2 standards, as well as other topics related to product data exchange and engineering database systems.


Dr. Loffredo received PhD and Master of Science degrees from Rensselaer Polytechnic Institute, as well as Bachelor of Science degrees in both Physics and Computer Science from the State University of New York.

Selected Publications

  • Loffredo, D., editor, ISO 10303-238:2022 (third edition), Industrial Automation Systems and Integration — Product Data Representation and Exchange — Part 238: Application protocol: Model based integrated manufacturing, Geneva, International Organization for Standardization. ISO TC184/SC4 WG15 N196. Also first (2007) and second (2020) editions.
  • Loffredo, D., “ISO 10303-238: An Integrated Protocol for NC Machining, ” in Interoperability for Digital Engineering Systems, A. Moreno, Ed, Milan, Italy, FrancoAngeli, 2014, pp. 141-153. ISBN 978-88-917-0600-3.
  • M. Hardwick, D. Loffredo, J. Fritz, M. Hedlind, “Enabling the Crowd Sourcing of Very Large Product Models,” Digital Product and Process Development Systems - IFIP TC 5 International Conference, NEW PROLAMAT 2013, Dresden, Germany, October 10-11, 2013. pp 254-272. doi: 10.1007/978-3-642-41329-2_26, also here
  • M. Hardwick, Y. F. Zhao, F. M. Proctor, A. Nassehi, X. Xu, S. Venkatesh, D. Odendahl, L. Xu, M. Hedlind, M. Lundgren, L. Maggiano, D. Loffredo, J. Fritz, B. Olsson, J. Garrido, A Brail, “A roadmap for STEP-NC-enabled interoperable manufacturing,” The International Journal of Advanced Manufacturing Technology, 2013, doi: 10.1007/s00170-013-4894-0
  • Hardwick, M. and Loffredo, D., “Challenges and Choices in the Specification and Implementation of the STEP-NC AP-238 Standard,” Journal of Computing and Information Science in Engineering, Vol. 7, No. 3, September 2007, doi: 10.1115/1.2768090
  • Hardwick, M. and Loffredo, D., “Lessons Learned Implementing STEP-NC AP-238,” International Journal of Computer Integrated Manufacturing, Vol. 19, No. 6, September 2006, pp. 523-532, doi: 10.1080/09511920600627170
  • Hardwick, M. and Loffredo, D., “The STEP International Data Standard Evolves into Manufacturing,” Journal of the Japan Society for Precision Engineering, ISSN 0912-0289, Vol. 67, No. 5, May 2001, pp. 733-738.