According to James H. Gilmore & B. Joseph Pine II in their 1997 essay, there are four defining approaches to Mass Customization:
Collaborative: Where customers conduct a dialogue with businesses to identify their needs, and a customized product is made to fulfill their specifications.
Adaptive: Companies produce a standardized product that is customizable in the hands of the consumer.
Transparent: Manufacturers provide individual customers with unique products, without explicitly telling them that the products are customized. The importance of research into consumer needs is critical here.
& Cosmetic: Is when a company produces a standard product but package differently for different customers (especially in business to business scenarios)
Currently what is important in all instances as far as the manufacturer is concerned is that they only allow mass customization of those parts which will provide the most differentiation to the consumer, yet as little variation as possible to make it economically viable.
This angle of approach may slowly be changing as more niche markets and bespoke producers start to compete with larger corporations. Armed with digital manufacturing technologies these smaller, nimble manufacturers will increasingly be able to produce more individualized products primarily using collaborative and adaptive techniques.