A row in an accumulating snapshot fact table summarizes the measurement events occurring at predictable steps between the beginning and the end of a process. Pipeline or workﬂow processes, such as order fulﬁllment or claim processing, that have a deﬁned start point, standard intermediate steps, and deﬁned end point can be modeled with this type of fact table. There is a date foreign key in the fact table for each critical milestone in the process. An individual row in an accumulating snapshot fact table, corresponding for instance to a line on an order, is initially inserted when the order line is created. As pipeline progress occurs, the accumulating fact table row is revisited and updated. This consistent updating of accumulating snapshot fact rows is unique among the three types of fact tables. In addition to the date foreign keys associated with each critical process step, accumulating snapshot fact tables contain foreign keys for other dimensions and optionally contain degenerate dimensions. They often include numeric lag measurements consistent with the grain, along with milestone completion counters.