1. A non-transitory computer-readable storage medium storing a program product for planning an assortment of articles, the program product comprising machine-readable program code for causing, when executed, one or more machines to perform the following method steps: receiving data representing a plurality of articles and an assortment, the assortment data including a plurality of store attributes, wherein the plurality of store attributes includes sales volume, merchandise category data, and store demographics; upon a user assigning a first subset of the plurality of articles to the assortment for a first validity period and releasing the assortment, automatically defining a first assortment version; assigning a plurality of stores to the assortment based on the plurality of store attributes associated with the assortment; determining a layout module representing a physical display area of a store of the plurality of stores to which one or more articles and one or more fixtures can be assigned; assigning one or more articles from the first subset of the plurality of articles to the layout module; and assigning the layout module to the assortment, wherein when the assortment is released, a first layout module version is automatically created corresponding to the first assortment version, wherein the first subset of the plurality of articles assigned to the first assortment version are assigned to the first layout module version and a validity period of the first layout module version is assigned the first validity period associated with the first assortment version, wherein the first layout module version is for use in each of the stores.