A method for planning a process of cutting human or animal bone tissue (9) comprises: obtaining initial data of an initial situation of the bone tissue (9)； defining target data of a target situation of the bone tissue (9)； and computing a cut geometry using the initial data and the target data for cutting the bone tissue (9) apart. The cut geometry comprises a structure being shaped such that the bone tissue (9) is reassemblable in an at least in one degree of freedom distinct manner in the target situation after being cut apart along the cut geometry. By shaping the structure of the cut geometry in accordance with the target situation of the bone the planned cut can be provided with a particular function. I.e., such a functional cut can geometrically define and restrict possible movements of cut apart bone portions in relation to each other. Thereby, the functional cut can allow for comparably precisely repositioning the bone into the target position and any movement therefrom at least in the one degree of freedom can be prevented. Thus, the method according to the invention allows for cutting bone tissue whereas reassembling cut apart portions of the bone tissue in accordance with the intended application is already initially considered. Thereby, it is possible to assure that the bone tissue can be comparably precisely and stably reassembled in the target position without mandatorily requiring additional fixing means or the like. Inaccuracies of manual or similar positioning of the cut apart bone portions while reassembling can be minimized or even excluded.Une méthode de planification d'un processus de découpe de tissus osseux humains ou animaux (9) comprend : l'obtention de données initiales d'une situation initiale des tissus osseux (9)； la définition des données cibles d'une situation cible des tissus osseux (9)； et le calcul d'une géométrie de découpe en utilisant les données initiales et les données cibles pour la découpe et la séparation des tissus osseux
