In this article it is displayed how a model for asset allocation which reproduces the judgement-making process of an expert (via concepts based on fuzzy logic) can be individualised and extended in order to adapt it to the judgement-making process of other experts. Here, even after wide-ranging changes and additions, the advantages of the fuzzy approach remain, which consist of its flexibility, its realistic reproduction of expert knowledge and the comprehensibility of its results. In order to clarify the procedure, typical adaptation and extension requests for an asset allocation model are presented. The steps towards their implementation are shown on an application which was developed under the expert supervision of a leading international capital investment company. The composition of the examples shown is based on experiences from several presentations in which the model was presented to various financial service providers.