Part

The core aspect of PLM is of course Part. Understanding it is crucial for any PLM practitioner. At the surface level it looks simpler, and one may even ask "Part is a part" and what more is there to understand in it. In this post we will go beneath the surface and explore various nuances of Part.

A "Part" can be defined as "The thing that has form, fit and function and is the whole or part of a product". The word Part is used to mean both the Design and the instances of the design depending on the context. In Engineering and PLM context Part will mean the Design and in Manufacturing, Sales, Service it may mean the instance of Design. Design Parts are uniquely identified with Part Number and Revision and Part Instances are normally identified with series or batch number. Since we are discussing about Part in the context of PLM hereafter in this post Part means Design Part unless specified otherwise.

While defining Part we mentioned the concept of Form, Fit and Function. What is form fit function?

Form : It refers to physical attributes of the Part. It may be shape, dimensions like length, width or height, weight, density, material composition, file size, file format.

Fit : It is the acceptable tolerance of the values of form and/or function attributes. For example if a rod's diameter is specified as 3+/-1% cm, 3cm diameter is the form and the acceptable tolerance range of 2.97 cm to 3.03 cm is the fit. A fit needs to be specified because, it is impossible to manufacture a part to a precise dimension. An acceptable tolerance limit will help a part to properly work in an assembly as per expectations.

Function : Function is the the objective of the part. Though function is derived from the form and fit, function may need to be explicitly specified because form and fit may not be defined in too much detail. So an intention of the function like "2ohm resistance"  needs to be specified instead of defining the underlying material and technical form of the resistor achieve a 2ohm resistance output.