Check out this highly informative story by Jonathan Bues in Watch Journal about Parmigiani Fleurier's comprehensive in-house watchmaking.
Click the link after the excerpt for the full story.
While many larger brands enlist third parties—who also happen to be their competitors—to source the most important components, Parmigiani Fleurier performs almost every watch manufacturing function itself. It has even turned the normal Swiss watchmaking equation on its head, becoming a supplier to many larger, group-owned marques.
Parmigiani Fleurier watches are crafted in a handful of highly specialized workshops that include Vaucher (the movement maker), Elwin (screws, wheels, and pinions), Altokalpa (escapements), Les Artisans Boîtiers (cases), and Quadrance et Habillage (dials). This arrangement, known as etablissage in French, has its roots in the early history of Swiss watchmaking. During harsh winters, Swiss farmers in Fleurier, the Vallée de Joux, and other rural areas receded into their farmhouses to practice a single, highly specialized horological trade. Making one component, and doing it well, guaranteed a steady source of income through the lean winter months, when the local fields and valleys lay blanketed with snow. The farmhouses and barns of yesteryear may be gone, but the principle of extreme specialization prevails. The parts made in Parmigiani-owned facilities continue to support some of the biggest names in contemporary fine watchmaking by lending excess capacity and supplying dials, cases, screws, and more to companies such as A. Lange & Söhne, Greubel Forsey, Zenith, and more.