The service of every watch whether its a quartz or mechanical watch includes complete disassembly of all the movement. Each part is carefully examined for damage or wear and where necessary replaced or repaired. The watch is cleaned while disassembled and is then again inspected whilst being reassembled. The watch is carefully checked and where necessary adjusted to ensure optimum performance. re parts to independent watchmakers which prevents all but authorised service centres from working on certain watches with official parts. Achieving brand authorisation often requires a significant investment in specific tooling and equipment required by the brands. While the equipment check lists issued by the various brands frequently feature equipment of similar specification, the brands often require equipment from differing manufacturers, which might result in an independent watchmaker or service centre having to purchase several different pieces of equipment capable of the same job if it wishes to work on watches from more than one brand.