A modification is a generic definition of high-level definitions of service bulletins, airworthiness directives and other sundry change or maintenance request definitions for an engine type (or a top-level part). A modification on a part might actually require different work activities and/or spare parts be used on the part, or on its components. The components that are impacted by a modification (because work is performed on them) are called affected parts. For example, a modification on a jet engine might require that work be done on the three main rotor hubs of the Fan Module subassembly. The modification is defined as being on the jet engine, with affected parts being the rotor hubs that are actually two or three levels down in the overall jet engine structure.
A modification might be defined with a comply and a
de-comply definition; the comply definition would describe how to perform the
modification while the de-comply would describe how to back out of the
modification after it was successfully performed.
Within IFS/Complex Assembly MRO, the handling of these modifications during an engine visit
would be handled through a series of repair shop orders generated during the
Disposition process. As parts are inspected during the Disposition process, the
inspector will also be noting any modifications in which the part being
inspected would be an affected part, and the inspector would be marking the part
to be handled for the modification. This would cause the Disposition process to
look at the modification definition in IFS Manufacturing to find the allocations
and/or operations needed to perform the modification on the affected part being dispositioned.
Because the data to create allocations and operations is not present in
IFS/Fleet and Asset Management and
would only be used by shop orders, the intent is to take the modification
information in IFS/Fleet and Asset Management and transfer it into IFS Manufacturing, so that
repair codes can
be associated to point out the allocations and operations needed to do the work.
An alternative is to assign repair codes to affected parts whilst setting up the
modification, prior to its transfer to manufacturing. Modifications may be transferred manually or
automatically. A manual transfer requires the user to select the relevant menu
option that will transfer all valid modifications for the structure of the top
part to the given site(s). An automatic transfer is initiated when a
modification, that has affected parts defined for it, is activated. The
automatic transfer will only be done to valid sites to which the user is
allowed. If repair
codes are assigned to affected parts on the modification, these repair codes
will be transferred along with the affected part information to the valid sites
for active modifications.
A manual retransfer of modification data to manufacturing may be done to handle situations where a modification in IFS/Fleet and Asset Management has not been transferred to a required site, e.g., the user who activated the modification does not have access to the site, or to deal with changes to the definition of the modification after the transfer was made.