1. A method of updating object data with respect to object specifications in a product life cycle management system comprising objects, dependence relations between objects and object specifications, the method comprising: building a directed graph comprising nodes and arcs, wherein: a node of the graph represents an object of the system; and an arc of the graph is directed from a second object to a first object, the first object depending on the second object according to a dependence relation; and updating object data of identified objects based on object specifications of the system by browsing the graph according to a direction of the directed arcs of the graph.