Product Scope + Project Scope = Work Scope
One of the first things you have to do as an engineering project manager is fully define the scope of work your team is responsible for creating. You can’t build something unless and until you know exactly what that “something” is supposed to be. That “something” is the Scope of your project.
The total Work Scope of a project is comprised of two fundament components:
Product Scope (i.e., the deliverable itself); and
Project Scope (i.e., all the supporting work required to produce the deliverable).
Both Product and Project Scope are captured in the Project’s WBS, or Work Breakdown Structure. This is usually displayed in a hierarchical tree structure as shown in the image:
The Product Scope portion of the WBS is commonly referred to as the PBS, or Product Breakdown Structure. This is simply a subset of the overall WBS. It represents the Project’s primary “deliverable.”
The Project Scope represents the various services and functions that are required to produce and deliver the Product Scope. For instance, Systems Engineering and Project Management are work that must be performed to help support the design, analysis, fabrication, test, rework, re-test, assembly, packaging, and shipping of a subsystem of the deliverable.
Note that the elements of a WBS are not “tasks” or “activities” that need to be performed, but rather products and services that need to be delivered. Tasks and activities are captured in the Project Schedule, not the WBS.