A task of product-based planning in PRINCE2 is to write the Project Product Description. This is part of defining and documenting the project's output, outcome, and benefits, which are crucial for planning the project effectively. References: PRINCE2 Foundation official documentation and study materials.

The purpose of the 'Initiating a Project' process in PRINCE2 is to establish solid foundations for the project, ensuring that there is a common understanding of the reasons for the project, the expected benefits, how it will be managed, and what its products should deliver. References: PRINCE2 Foundation Training Manual; PRINCE2 2017 Foundation handbook.

In the PRINCE2 customer/supplier environment, it is typically the customer's responsibility to specify the desired result of the project. This responsibility involves defining what the project should achieve in terms of outcomes and benefits, aligning with the customer's business objectives. References: PRINCE2 Foundation official study materials.

PRINCE2 defines three levels of planning: Project Plan, Stage Plan, and Team Plan. The Team Plan is one of these three levels, specifically designed to manage the delivery of the work packages assigned to the team within a management stage. References: PRINCE2 Foundation official documentation and study materials.

The 'learn from experience' principle in PRINCE2 encourages continuous learning and adaptation within the project team. By applying this principle, teams are able to capture and act upon lessons learned throughout the project, thereby identifying and implementing improvements in real-time, which can enhance project outcomes.
= PRINCE2 7 Foundation handbook and online resources