Wikipedia
Custom-fit means personalized with regard to shape and size. A customized product would imply the modification of some of its characteristics according to the customers requirements such as with a custom car. However, when fit is added to the term, customization could give the idea of both the geometric characteristics of the body and the individual customer requirements, e.g., the steering wheel of the Formula 1 driver Fernando Alonso.
The custom-fit concept can be understood as the idea of offering one-of-a-kind products that, due to their intrinsic characteristics and use, can be totally adapted to geometric characteristics in order to meet the user requirements.
With this new concept, industry moves from a resource based manufacturing system to a knowledge based manufacturing system and from mass production to individual production. This encourages the Lean Production trend as established by Toyota, or in other words, an efficiency-based production.