The existence of countless proprietary file formats and the exchange of 3D CAD data has been a significant problem since the beginning of 3D CAD modeling. CAD applications and methods using digital data are constantly changing, which predicates the need for a solution to share validated and accurately translated data, thus the birth of STEP242

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A STEP forward for Product Lifecycle Management
INTRODUCTION
The existence of countless proprietary file formats and the exchange of 3D CAD data has been a
significant problem since the beginning of 3D CAD modeling. CAD applications and methods using
digital data are constantly changing, which predicates the need for a solution to share validated and
accurately translated data, thus the birth of STEP242. Companies who are adopting Model-based
processes and tools within their organizations are using ISO 10303 STEP Application Protocols AP242
and AP239 for both exchanging data as well as maintaining data for archival and retrieval. Long Term
Data Archival and Retrieval (LOTAR) http://www.lotar-international.org, is an International project
sponsored by multiple consortiums for the standardization of the archival and retrieval of digital product
and technical data. This project is ISO compliant and works across multi-CAD environments enabling
stake holders to share 3D data within a Model-Based Environment (MBE) or a digital enterprise. To
ensure the preservation of design intent; validation properties which include geometric shape
representation, assembly features, saved views, user-defined attributes, color, visibility, and Product &
Manufacturing Information (PMI) 3D data needs to be verified and validated for compliance. The
culmination of these standards is allowing companies around the globe to manage interoperability with
fewer challenges.
Government regulators are enforcing the need to retain digital documents indefinitely for legal,
administrative and historical purposes. Dealing with government guidelines, the advent of MBE and the
preservation of digital data necessitates the need for an approved process for managing this type of
data. Many OEMs and suppliers are grappling with the notion of how to preserve electronic documents
and information for 70+ years. Some of the issues they face include estimating the lifespan of storage
materials, the potential obsolescence of file formats, upward and backward compatibility of applications
and operating systems, and whether existing methods of reading data will be viable in the future.
AP242 is the replacement of standards AP203 and AP214. AP242ed1 was released in 2014, and edition
2 is well on its way to being released by the end of 2019. Although neutral formats are not the holy grail,
the externalities to this format is the benefit of the consumption of downstream applications in the
Computer Aided Engineering (CAE), Computer Aided Manufacturing (CAM) and Coordinate Measuring
Systems (CM) domains. The provocative implementation of AP242 has been addressed in many studies
at NIST1
. CoreTechnologie (CT) can releve the burden within companies and is often approached to

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make some sense of the countless requirements and standards. They are finding a proactive approach
to this fast-changing industry as well as providing the necessary automation required within PLM
applications. This paper will explain how these important standards can be successful while using
3D_Evolution™ software developed by CT. This software also enables the ability to write out these
standard requirements in other formats such as JT OPEN.
THE AIRBUS STORY
One of the key driving forces behind the creation of LOTAR is the now famous case study of the Airbus
380 - when engineers in Germany and Spain were using a version of CATIA V4, and French and British
offices had upgraded to CATIA V5. This meant the German teams could not add their design changes for
electrical wiring back into the common three-dimensional digital mockup in France. Because of issues
like these, engineering system managers are grabbing the technology as a solution from its indigenous
prototypes STEP 214, and 203.
The mission of LOTAR is to develop a global standard based on archival and retrieval mechanisms for
digital product and technical information. LOTAR will achieve this through the ongoing harmonization
and standardization efforts of Aerospace and Defense affiliations and their common objectives. I have
seen the adoption of other industries, as Daimler is using the AP242 to support its MBE collaboration -
manufacturing information (PMI) integrated with models and embedding it within the JTOpen file
format and 3D PDF. Once the standards are written in a statement of work, they are then passed on to
PDES (USA governing body) https://pdesinc.org/ and ProStep (European governing body) to define specific
projects. The consortium members, PDES and the implementor forum (CAxIF) would then develop the
requirements. As part of the goals for archival and retrieval, the resulting projects will seek to enable
data exchange and interoperability mechanisms to ensure long term use of the digital product and
technical information.2
Interactions with the Aerospace & Defense PLM Action Group aims at
strengthening the communication of business requirements between users, implementors,
standardization bodies, and regulatory authorities such as EASA and FAA. The Engineering Analysis and
Simulation team has reached an agreement with NAFEMS to mutually benefit from expertise related to
CAE and long-term archiving with AP209 Ed.2. With the near-term availability of AP242 Ed.2 as Draft
International Standard, the Electric Harness group will support the launch of an implementor forum in
this domain, as part of the CAx-IF, based on pilot projects conducted to support the development of the
data model. Ea h o pa ’s odeli g pra ti e ill dra that disti tio differe tl . For e a ple,
export control limitations could be represented inside the MBD dataset or as a BOM attribute or both,
depe di g o the o pa ’s desig pra ti es. As stated by Simon Frechette at NIST.

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INDUSTRY REQUIREMENTS
Ma OEM’s have set guidelines on ho to address a er o o pra ti e that takes pla e i toda ’s
world of 3D CAD collaboration.
Each arrow in the above diagram could potentially be a conversion of one 3D CAD format to another. It
is quite easy to see how information has the potential to be lost at any point during the process. This is
partially due to different modeling kernels, which can compromise data integrity. LOTAR and other
organizations have put forth recommendations on how to make this process less complex and ensure
that a standards based approach is taken during the conversion, storage, and validation of the format.
METHODOLOGY
CoreTechnologie has followed the LOTAR recommendation and
has applied it to its suite of software - 3D_Evolution &
3D_Analyzer to support all three major points: Conversion,
Storage, and Validation.
VALIDATION
CT is the first interoperability company to develop the method of
checking the validation properties of STEP AP242 files based on
the recommended practices of LOTAR and its implementor forum
PDES. File Validation is an important process for both sharing and
storing data for future reference.

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CT originally developed this functionality for Airbus, as Jean-Yves Delaunay is known to be a subject
matter expert at Airbus and has assisted in defining the
requirements at LOTAR and has written numerous papers over the
past ten years Use of ISO 10303 AP242 in the European A&D
Industries. Using STEP AP242 satisfies the strict regulating
requirements facing aerospace and defense companies. Validation
reports were also developed using the direct feedback and
recommendations of Airbus whose main concern was to satisfy the
regulatory requirements of its government. There are three
reporting options available: HTML, CSV, & txt. The HTML format
provides a graphical representation of the many validation checks
available.
ARCHIVE/STORAGE
Governmental bodies around the globe are increasingly enforcing
regulations for Aerospace companies to retain digital documents
indefinitely for legal, administrative or historical purposes for as
long as the airplane(s) remains flying. ISO 10303 AP242 is at the
basis of how the LOTAR organization recommends the format of
the digital data be stored for the foreseeable future. A standards
base approach will ensure that future absorption of the data will
be at the same level of openness for all. LOTAR is also aiding in the
area of reducing the amount of storage space needed to house all
of this information in server vaults. By providing recommendations
on how to compress the STEP file format using an algorithm that
will be open for all implantations to use; as well as provide the
new file extension to be clearly understood that the STEP file is
compressed and will need to be uncompressed for use in the
future system.
CoreTechnologie has implemented the ability to batch process the conversion of native file formats with
its 3D_Evolution product in the STEP AP242 format, BO model XML, ISO 10303-21 and compressed files
recommended by LOTAR. This would allow IT departments to store and archive the digital data for years
to come in a Standards based method as well as save money when it comes to the amount of disk space
that would be required as in some cases file size reduction can be as much as 35%.
Validation Checker
Configuration
Geometric Validation
 Volume
 Area
 Centroid
 Cure Length
 COPS
Assembly
 Number of children
 Notional Solids
PMI
 Polyline Curve
Length
 Polyline Centroid
 Equivalent Unicode
String
 Affected Area
 Affected Curve
Length
 Number of
Annotation
 Number of View
Tessellation
 Centroid

STEP File Validation Options

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CONCLUSION
CoreTechnologie continues to look at its road map to understand standards in this ever-growing global
market requirements. CT has taken the necessary steps to align our suite of products to meet three of
the biggest challenges when it comes to meeting regulations set forth by governing bodies; Conversion,
Validation, and Archiving.
Interesting are the mandates that challenge software companies. Robert B. Reich stated it best in an
issue of the Har ard Busi ess Re ie , If ou feel as if go er e t a d OEM relatio ships are reathi g
down your neck, get used to it. For the foreseeable future, governments are going to take an especially
kee i terest i ho ou’re a agi g our usi ess. E e uti es should look for tighter s ruti that e
have seen for decades and new, [get] accustomed to ducking behind corporate and government
relations professionals, we will need to develop a new mindset and skill set that will allow them to
partner with the go er e t rather tha fe d it off.
For more Information
http://www.lotar-international.org/contact.html
https://pdesinc.org/contact/
David A. Selliman, Vice President
d.selliman@us.coretechnologie.com
REFERENCES
1. https://www.nist.gov/publications/portrait-iso-step-tolerancing-standard-enabler-smart-manufacturing-
systems
2. http://www.lotar-international.org/development-space/lotar-workgroups/3d-cad-with-pmi.html
3. http://www.lotar-international.org/why-lotar/mission-objectives-scope.html
4. http://www.cax-if.org/documents/rec_prac_gvp_v31.pdf
5. http://edocket.access.gpo.gov/cfr_2010/janqtr/pdf/14cfr21.137.pdf
6. http://www.boeingsuppliers.com/supplier/DPD_Task_Guide.pdf
7. https://www.supplier.cessna.com/quality/requirements_for_engineering_projects.pdf