In the decision of July 17, 2012 (X ZR 97/11 „Palettenbehälter II“)

the German Federal Supreme Court has defined the patent-free exchange of parts versus a patent infringing new-manufacture. A decisive criterion is whether the exchange is according to the customary usage in the trade is a matter of usual maintenance, which does not change the identity of the complete product as a marketable economic good. One further aspect is whether the exchange of the part in question is usually to be expected during the lifetime of the protected product.