The management of the interfaces is one of the keys of the project management, everyone speaks about it but nobody can really identify them, these interfaces. With 3DWBS method, I am able to find them, mathematically and automatically, starting from the schedule and the WBS of the project. An interface is a risk, it is managed like a risk. It is necessary to identify the hard points of the project (interfaces) to treat them when they become reality. Moreover, nobody knows really what is an interface. An interface takes place at the same time when two tasks are carried out in parallel. An interface thus has a duration. But all the tasks in parallel are not in interface, only some of them are. 3D WBS method precisely makes it possible to calculate those which correspond indeed to interfaces by evaluating their criticality and their complexity. It is a question of distance between the tasks within WBS cube. In work (WBS), all has three dimensions, and even the interfaces. Then there are interfaces of Zones (geographical), Products (physical) and Activities (logical, temporal). For example, if two tasks take place at the same place, it is an interface of Zone; If I install the transformer then I connect cables above, it is a Product interface; If I prepare the ground then I do the earthworks, it is an interface of the Activity type. 3D WBS method thus makes it possible to generate the list of the interfaces of the project, which is an innovation! Then, when they are identified, they are managed like the risks: they are classified, prioritized, treated, then capitalized.
