A computer-implemented method of performing a product availability check comprises the step of receiving information on a plurality of first
electronic data sets, each of which includes a first key and a product quantity in relation to a
single point of time or time period. The first key includes a
primary key element and a plurality of secondary key elements representative of product-related conditions each. The method further comprises the step of deriving, based on the information on the first data sets, information on one or more second
electronic data sets, each of which includes a second key and product quantities in relation to a series of points of time or time periods. The second key is formed exclusively of the secondary key elements. Based on the information on the one or more second data sets, result information on the availability of one or more products in dependence of time and the primary and secondary key elements is then derived. According to the invention, the information on the one or more second data sets is generated to further include in each second
data set one or more auxiliary data structures, each auxiliary
data structure including one or more auxiliary data elements, each auxiliary
data element including the
primary key element, product quantity and point of time or time period as included in a respective first
data set that contributes to the time-dependent product quantities in the corresponding second
data set.