The watchmaker completely disassembles the movement by hand, part by part. This involves around one hundred parts for the simplest models and up to two hundred for the most complicated.

Each part is cleaned in a series of special baths to remove all residual traces of lubricant.

The watchmaker then checks the condition of all of the components that make up the movement. Any that are worn or no longer comply with Piaget's high quality criteria are systematically replaced.

The battery in quartz watches is also replaced. The watchmaker then reassembles the movement by hand and adjusts and checks its various functions. He then lubricates the movement: this is a complex operation that involves several special oils in strictly controlled amounts.

To finish, he checks the operation of the movement and makes any final adjustments that may be required.