The invention relates to a method for automatically preparing a working plan for producing a product comprised of several components, e.g. a wire harness. The inventive method involves the following steps: a) providing a product data model of the product, in which each component is described by a partial data set containing a classification characteristic; b) preparing a database, whereby the data sets contained therein are divided into classes according to the classification characteristic, whereby each class contains one or more selection rules, whereby a manufacturing partial process provided with an index is assigned to each selection rule, and each manufacturing partial process contains one or more working cycles; c) automatically selecting the class applying to the component by using the classification characteristic; d) automatically selecting a manufacturing partial process suited for producing the component by using the selection rule; e) automatically establishing the sequence of the manufacturing partial processes by using the respective index.