Mirror, mirror, on the wall...is the new release any different at all? [BDDs]

Reduced, ordered binary decision diagrams (here, simply BDDs) have been adopted as an important data structure for a number of applications, ranging from logic design verification to logic minimization and technology mapping. However, for a number of functions that arise in practical applications, the size of the BDD data structure depends critically on the choice of the variable order: a poor order may lead to a data structure whose size grows exponentially with the number of variables. Finding an order that minimizes the size of BDDs is NP-hard; the development of heuristics for computing better variable orders is an ongoing area of research. In this paper, a design of experiments methodology is applied to the study of the behavior of software packages which construct and manipulate BDDs