A project plan timeline is an official document that outlines the steps and activities required to complete a project. It is a critical component of any successful project and is used to track progress, identify potential risks, and ensure that the project is completed on time and within budget. The timeline typically includes a timeline of tasks, milestones, and deliverables, as well as an estimate of the resources needed to complete the project. It also includes a schedule of when each task should be completed and the associated costs. The timeline should be regularly updated to ensure that the project is on track and that any changes or delays are addressed in a timely manner. A project plan timeline is an essential tool for any project manager and should be used to ensure that the project is completed successfully.