Disassembly is one of the key elements of any processing of recovered products. Be it for repair, remanufacturing, refurbishing, cannibalisation, material recycling, or disposal. Hence, planning the disassembly is important and--with growing amounts of recovered products and need for saving resources--becomes even more important. The disassembly planning approaches presented are based on mathematical programming. With this methodology, a profit-optimal planning of quantities of multiple types of recovered products as well as parts distribution, material recycling, and disposal quantities is realised. Thereby, typical aspects, like material purity requirements, the condition of the recovered products, hazardous parts, and capacity limitations, are also considered. A new approach is the presented combination of disassembly-to-order planning and disassembly sequencing, which is called Flexible Disassembly Planning.