Form Fit Function Rules

The part s dimensions shape weight size material and visual appearance.

Form fit function rules. If your warehouse is locating non interchangeable parts by revision then the revision has become a de facto part number suffix. Tightening a bolt that holds parts together or applying paint are both examples of steps that change form fit or function. The updated item is said to be form fit function and interface compatible when it can be inserted into the existing system without impacting system operation. Form fit function rules specify how far new versions of a part can deviate from the original before new part numbers are created.

Form fit and function are also a good litmus test against which to check if a process step is value added or not. This is the reason for. Created for sebok 2 a mechanism to link design to performance requirements. These rules help companies decide whether a product change should require a new item number or simply a revision of the same item number.

If a step changes the form fit or function of a product it is probably value added. Form fit and function are subjective terms. Typically if the change to a part is significant enough that the new part cannot be used in place of the previous version for example if the size of a screw changes then a new part number must be created. Form fit and function f3 is the identification and description of characteristics of a part or assembly.

This is key in ensuring components can be substituted without issue. To prevent any confusion the f3 rule defines each word as follows. The standard form fit and function f f f definition has served the needs of discrete manufacturers well for a long time. Form fit and function rules specify how much new revisions of a part can deviate from the original before new part numbers are created.

Fit is the ability of an item to physically interface or interconnect with or become an integral part of another assembly. Form fit and function. Each defines a specific aspect of the part to help engineers match parts to needs. The f3 framework increases design change flexibility by allowing changes to the part with minimal documentation and design cost as long as the fit form and function of the product are maintained.

During the design process engineers regularly have to decide on whether a new part or change meets the form fit and functional. Of course the whole point of using the form fit function rule is to decide when a part iteration requires a new number and inventory location. Form fit function is not a very good way of fully describing what changes need a part number change rather than revision at least to asme y14 100 series see section 6 8 of 2004 version. The best summarized test is interchangeability not just on form fit function but in every conceivable way including any requirement for trace.

The part s ability of the part to interface with connect to or join with other features of the assembly. I e replacing an item system based on form fit function and interface characteristics.