Engineering Change Order

An Engineering Change Order (usually given as the acronym, ECO) is an important piece of the paper trail for maintenance of a piece of equipment. If is a directive from the engineering organization, to both the manufacturing organization (for units yet to be built), and also to field service (for units already deployed) specifying a change in the design/implementation of a device - usually to correct an error which was not discovered until after the design had been 'frozen' and released from engineering.