Managing Product Delivery.
PRINCE2 states that the project manager’s job is to manage the work not to do it. In other words the creation of the specialist products are the responsibility of the specialist team. The project manager uses the Controlling a Stage process, while the specialist team, and the team manager if appointed, use the Managing Product Delivery process.
Therefore the Managing Product Delivery process acts as the link between project manager and team managers where the emphasis is on accepting a Work Package, executing a Work Package and delivering a Work Package.
Each Work Package must contain at least one Product Description, and the role of the team manager is to coordinate that area of work. Several Work Packages may be given out at any one time to different specialist teams, or they may be given out in series to one team. At a minimum, one Work Package may be given out in a particular management stage.

It would be chaotic to think that the team carry out any work that they think is necessary without the authority of the project manager. Therefore work allocated to the specialist team can only start once it has been authorised and agreed between the project manager and the team managers.
The information contained within the Work Package clarifies exactly what is to be produced what is the expected work at that, costs and timescales. This ensures that the planned products are delivered to expectations and within tolerance if this is applied.
It is also important that accurate progress information is given on an agreed regular basis to the project manager (this is done via the regular Checkpoint Reports), so that the project manager can assure themselves that work is proceeding to plan and that the products are being created to a satisfactory level of quality.
Managing Product Delivery will be triggered by the project manager authorising a Work Package and this must be accepted by the team manager or the team members themselves. As part of accepting the Work Package, a Team Plan may be created, although if needed, this is often done in parallel with creation of the relevant Stage Plan.
The information within the work package will ensure that the products are developed in line with any specified development methods, and the product descriptions included will describe the quality methods and quality criteria that each product must meet.
For a product to be completed, there are three steps: first the product must be created to its draft status, then the quality check all quality review is carried out, and if successful the product then needs to be approved. The quality check and the approval must be independent of those creating the product in the first place.
The formality of the work package may differ depending upon whether the specialist team are internal to the organisation or a third party organisation, in which case the work package may form part of the work statement contained within a contract.