1.1.2 Solution: Standards for Packaging Together Files

To address these challenges, Energistics and its members have developed a file packaging convention based on the Open Packaging Conventions (OPC), a widely used container-file technology that allows multiple types of files to be bundled together into a single package. Built on the widely used ZIP file structure and originally created by Microsoft, OPC is now an open standard supported by these standards organizations:

• Ecma International (http://www.ecma-international.org/publications/standards/Ecma-376.htm )

• ISO/IEC 29500-2:2012, which has 4 parts, which are all freely available at this link (near bottom of the page) (http://standards.iso.org/ittf/PubliclyAvailableStandards/index.html ).

Energistics has adopted all of these practices and adapted them to meet the needs of its data-exchange standards, beginning with RESQML V2.0.

• This tailoring of OPC is referred to as the Energistics Packaging Conventions (EPC).

• The resulting package that contains all of the component files is referred to as an EPC file (or sometimes an Energistics package).

IMPORTANT! IT professionals implementing EPC MUST use either OPC libraries or the OPC specification for the majority of their coding. Use this EPC specification to implement the EPC adaptations, which are explained in Chapter 3 EPC-Specific Content and Structure.