The Project Tasks Planning message is used in various industry sectors when there is a requirement for all parties involved to formally establish and exchange planning and scheduling information.  This information describes the tasks and resources needed to complete a project or provide a service.  This can include such details as what activities or tasks are involved, who is available to do the work, who is doing the work, what must be completed or delivered such as a document or goods, and when the work will be completed or when the item will be delivered.  This document may be part of the contractual documents exchanged for the preparation, status, or completion of a project or service.