In the Product Scope Description part of the project management plan you will find a statement that includes information about the project. This information usually has to do with the characteristics of the product. However, there is much more to it than just this. It is important to understand this because you will find that the characteristics that you will be writing about will oftentimes affect the activity sequencing part of the project management. Essentially, the activity sequencing will tell you what steps will need to be taken and in what order. Whenever you are talking about the construction of the physical layout of a plant or a subsystem interface that has to do with a software project, you will want to make sure that you are perfectly clear whenever you come to the activity sequencing part of the Product Scope Description. Otherwise the project management can become quite messed up. Oftentimes you will notice that the effects will be apparent within the activity list itself. However, you will still want to make sure that you take your time and spend some time reviewing the Product Scope Description itself in order to make sure that it is accurate.
This term is defined in the 3rd and the 4th edition of the PMBOK.