Product-based planning

Product-based planning is a fundamental part of the PRINCE2 approach to project management, and is a method of identifying all of the products (project deliverables) that make up or contribute to delivering the objectives of the project, and the associated work required to deliver them. The documents which define the Project itself are also considered Products.
Overview.
A significant advantage of product-based planning is the ability to surface critical assumptions and constraints. For example, if your project is to build another floor on top of a house a required "product" will be the floor underneath on which to build the one you are commissioned to deliver. As a "product" you hope that it is there and will be fit for purpose but as you are not commissioned to deliver it, it falls outside your scope - and into your assumptions. In this way, by defining the "whole" product set necessary for the project, and not just those that are in your scope, you can surface and document the critical assumptions. Another advantage compared to activity-based planning has to do with reporting. Products are either finished or not, activities can be 90% finished for a long time even though work is taking place. One tends to forget things that have to be done to complete a project. This method captures them all, reducing the chance that any will be overlooked.
This method is used in PRINCE2, the UK's government mandated method for the management of major projects
Example.
A refrigerator is a final product with sub-products being door, shelves, heat exchange unit, fans, ice cube dispensers, lights, etc.
Each of the sub-products are made up of smaller products such as door handle, insulation, magnetic closure strip and internal covering.