Downloaded from https://www.everyspec.com APPENDIX C MIL-STD-31000A models created in prior revisions, experience has shown that information from older models may be lost or distorted when read by current versions. Consequently, procedures must be developed to assure that models read from long-term storage faithfully match the original models put into the archive. These validation procedures should be performed regardless of whether long-term archives are in the proprietary formats of their originating CAD systems or in industry-standard formats such as ISO 10303 parts 203 or 214. Figure 10. Translation to archival format.
Presently, standards for long-term archival storage of 3D models are being developed and tested by two European organizations: the European Association of Aerospace Industries – Standardization (ASD-STAN) the ProSTEP iViP Association Three parts of the standard for LOng Term Archiving and Retrieval of digital technical product documentation (LOTAR) have been written and approved. Although these European standards are not binding upon the US Department of Defense, they represent the most thorough efforts to date to assure that 3D model-based designs that are stored for long periods are able to be read accurately by future systems.
Therefore adherence to LOTAR conventions, when possible, is recommended. 83