Change
A formal acknowledgement of intent to alter a baseline while maintaining control over a configuration. Note that the act of establishing a baseline in the first place (as for a new project) is considered the “base change” or “change zero”, which permits all baseline actions to fit into a single database structure.
Change Board
A group of people assigned to assess proposed changes to determine whether they are legitimate and, if so, adequately define the vertical and horizontal integration of associated tasks across a project. A good Change Board can make a project run very smoothly, even if management is idiots. A bad one can make an unrecoverable mess... read more
Class I Change
During the production phase, a change in design that requires prior approval from the Acquisition Customer because it threatens the applicability of the Qualification data on file. A Class I Change is an external change. Contrast with Class II Change. In this context, “threatens” more-or-less means any combination of the following: The revised design might... read more
Class II Change
During the production phase, any change in design that is NOT a Class I Change. A Class II Change is an external change. Contrast with Class I Change. The primary difference in the execution of a Class I Change vs. the execution of a Class II change is one of permission vs. forgiveness (respectively). If... read more
Effectivity
A type of accession identifier indicating an individual unit (or range) for an End Item, usually assigned during the contractual planning stage for any particular production run or series. Contrast with Serial Number and Line Number: Effectivity represents a contract planning sequence of an order being placed, S/N represents a manufacturing planning sequence, and L/N... read more
Engineering Change Proposal (ECP)
A proposal to the Acquisition Customer for the purpose of considering changes to the technical baseline of a program or project. In the early phases of development, an ECP is typically limited to technical requirement changes, although it is possible that small-scale changes to SoW and/or T&C will be necessary in order to effect the... read more
External Change Control
The situation where changes require authorization from the customer. See also Class I Change (a priori permission) and Class II Change (ex post facto concurrence), both of which are forms of “external” control during the production phase. Contrast with Internal Change Control.
Internal Change
An alteration of planned or intended cost, technical, or schedule content that is entirely in-scope to the contractual authority of the developer or supplier. Such a change does not require notification to the customer prior to incorporation into the design. Contrast with external change.
Major/Minor Determination
A process used by commercial aircraft developers to determine whether an existing certification remains applicable after incorporating some particular change in the design. This process lies close to the core of how the developer stays in business. The basis of the process is found in 14 CFR 21.93.a : “A ‘minor change’ is one that... read more
Program Change Proposal (PCP)
A proposed major change to a program’s SoW or T&C simultaneously impacting multiple clauses of both, including (but not limited to) changes in schedule and DIL. Contrast with the technical focus of an ECP.