PBS, Product Breakdown Structure or Products. Hierarchical tree structure of Products. Generally, PBS contains functional systems at the highest levels of the tree structure and physical components at the lowest levels of the tree structure. For example: ‘Technical specification’, ‘Calculation note’, ‘Project plan’, ‘Transformer’, Railway’, are products. It is the deliverables. More generally, ‘equipment’, ‘materials’ and ‘civil works components’ are pure Products. ‘Radio communication’ system is also contained in the PBS, it is a functional system but also a Product within the meaning “large”.
ABS, Activity Breakdown Structure or Activities. Hierarchical tree structure of Activities. An Activity is an Action, a set of Activities forms processes. An Activity can be a verb. For example ‘studies’, ‘design’, ‘purchase’, ‘construction’, ‘installation’ are Activities. An Activity is not a Task. Activities are deployed on Products, it is the processes that build Products.
ZBS, Zones Breakdown Structure or Zones. Hierarchical tree structure of Zones. ZBS is physico-funtional Zones, it can be geographical or functional. The meaning of ZBS depends of the project type. For an EPC (Engineering, Procurement, Construction) project, ZBS is group of functional systems for the design and the commissioning phases. And ZBS is geographical areas for the construction phase. For Product development project, ZBS is waves of prototypes. For IT projects, ZBS is released/functional increment/Target machine type. For example, Zones of a linear project can be defined by: ‘lines’, ‘sectors’, ‘stations/inter stations’ and ‘sections’. It is locations here. In the WBS elaboration algorithm, Zones are the destination of Product during the project life, Products are grouped by Zones or Products are assigned into Zones.
WBS, Work Breakdown Structure. Hierarchical tree structure of Work. WBS is the whole of work to be carried out within the framework of a project. The last levels of the WBS are the tasks. WBS is a crossing between Zones, Products and Activities.
Task. It is the last item of the WBS, the Task is included in the WBS. A task is not an Activity. Task is the Work.
OBS, Organization Breakdown Structure. Hierarchical tree structure of the organization. OBS is the internal vision of the company’s organization. OBS can also be the project team. For example, levels of OBS can be: ‘Departments’, ‘Services’, ‘Disciplines’, ‘Teams’. OBS is extended by RBS, Resource Breakdown Structure.
Project interfaces. Degree of interaction between two tasks. When there is an overlap between two tasks, it can be an interface but not always. There are three types of interfaces: Zone, Product and Activity. Criticity of the interface is given by the distance between two tasks, in the project cube. Complexity of the interface is given by the difference of task’s colors (OBS) in the visible spectrum of colors, in the WBS cube.