"This standard is a part of the NAS9300 Series. This standard addresses requirements for the long term archiving of digital product information@ applicable to the international aerospace industry. Data shall be available to meet regulatory@ legal@ contractual and business requirements. Initially@ this document sums up the main business requirements for long term archiving of digital product data. Although these requirements are not in themselves normative@ when making data available over an extended period@ it is a fundamental principle that the contextual data needed to interpret the data is also available. This standard uses the OAIS reference model to provide comparability with other approaches to keeping information available. However@ OAIS is a standard reference model for comparison@ not a standard for implementation. Consequently@ this document defines requirements for processes (and associated technologies) intended to make data available for the life of a product@ and does so in terms of the OAIS model. In dealing with traditional media@ the differences between substantial change and unimportant ""surface"" change are generally self-evident. For example@ the yellowing of paper over time@ or the encrustation of a gravestone with lichen do not loose the information contained@ whereas the loss of pages of a document@ or the erosion of the stone do so@ and archiving focuses on the preservation of the medium. For digital product data@ the medium is unimportant@ but the content can be corrupted. The subject of the (many) remaining parts of this standard is the identifciation of the information that shall be uncorrupted if digital product data is to be usable in the future@ and the consequent refinement of processes and procedures to insure this. This standard addresses@ archiving of digital product data required for product definition@ such as in three-dimensional representations a tolerances@ material properties@ manufacturing data@ etc@ specification call-outs@ product structure and configuration control data@ etc. Other parts of the NAS9300 standards will cover more specifically the long term archiving of@ for example@ composites@ electrical systems@ product analyses and product simulation information. This standard also addresses managing the evolution of technologies required to ensure the availability and usability of the data for the required archiving period. This standard is not intended to incorporate company specific requirements and does not dictate specific organizational structures within a company. This standard does not specify a design or an implementation of an archive system. Actual implementations may distribute responsibilities or break out functionality differently. This standard assumes that all requirements for configuration management of the product data are in place and therefore are not specifically described in this document. If an organization chooses to implement requirements beyond those outlined in this requirements document@ those additional requirements shall not conflict or negatively impact the requirements contained in this document. Purpose: This standard establishes legal and other business requirements for processes intended to preserve digital data. Data need to be stored and maintained so that data are retrievable and usable for the required archiving period. In addition@ for some business requirments@ data need to be authentically preserved and accessed. This standard is intended to allow for different implementations based on a company's specific business environment."