The purpose of a project schedule is to define how the project should be delivered and maintained based on the available resources. The development of a timetable is the first step in project planning. A project schedule shall also be used to provide the status of the project. 
A schedule that identifies major events or milestones in a project such as significant design events, start-up, turn-over to client, order long-lead-time components, mobilize in field, complete design, government reviews, and their timing. It is often the basis for contractual agreements between the owner and other team members. 
 Project Management Institute, A guide to the Project Management Body of Knowledge (PMBOK guide) (Pmbok(r) Guide), Sixth Edition. Project Management Institute, 2017.
 The Massachusetts Port Authority, 2015. BIM Guidelines for Vertical and Horizontal Construction.