WBS has horizontal usage method, vertical usage method and outline method. Project belongs to the outline method, which solves the relationship between various tasks. Vertical usage takes up too much space.
The advantage of product planning is that the chronological order between each product is clear, but for work that does not provide a product and has no deliverables, it cannot enter the process, and the concept of the product is too complex and changeable to grasp. WBS separates the work package from the definition of specific work, and adopts "the front to the package (work package), the latter to unpack". Unpacking is the decomposition of the parent work package into specific work. It gives the impression that it is not broken down to the end, and it is necessary to find a relationship after defining the specific work. This is a problem of using WBS.
In PRINCE2, a large-scale project management method designed and developed by the UK Government Department of Commerce (OGC), the role of the project manager is incompetent if he is not proficient in planning methods. Briefly, only describe the products of the major stage), the plan recognized and approved by the project management committee; during the project period, the stage plan should be continuously made in detail and directly implemented; for each project team, when the work package is authorized , but also to guide the project team to do a more detailed work package plan and review it. That is to say, PRINCE2 divides plans into three types: project plan, stage plan, and group plan. Corresponding various plans to PBS makes it much less difficult to establish a product breakdown structure. You don’t have to think about doing a whole-project, whole-process plan, which is hampered by the huge and complex product decomposition. A clear breakdown of the product is sufficient for planning.
Each project decomposition method has its own advantages, and there is no one-size-fits-all method to solve all problems. The key is to solve the problem.