Many pull policies can be found in the literature for controlling multistage production/inventory systems. In this paper, we present a framework that enables us to describe the dynamics of a large class of pull control policies, using the same set of canonical functions. The class of policies we consider here include well known pull policies, like kanban, CONWIP, basestock, generalized kanban, extended kanban, but also many other hybrid policies, and their extensions to systems producing batches. Each of these policies is characterized by the values of some parameters. These parameters values are calculated thanks to a computational algorithm that relies on the use of path algebra tools, especially (min,+) algebra tools. This canonical formulation allows to identify under which values of the control parameters, two different policies have the same dynamics behavior. It also enables to derive methods for evaluating and comparing the performance of several pull control policies, as we illustrate it in the paper.