This X12 Transaction Set contains the format and establishes then data contents of the Maintenance Service Order Transaction Set (650) for use within the context of an Electronic Data Interchange (EDI) environment. This transaction set provides a uniform, singular medium for the exchange of maintenance related information among organizations involved in the reporting, requesting, scheduling, planning, estimating, coordinating and performing of maintenance actions. It provides the structure to convey maintenance-related information, including maintenance action directives, maintenance actions, cost estimates, maintenance action assignments, maintenance action status, and completion reports. This transaction set can be used in a bi-directional environment alone or in conjunction with the Project Schedule Reporting Transaction Set (806) to link schedule and maintenance action information as well as with the Specifications/Technical Information Transaction Set (841) to link maintenance-related, media independent, technical data.