Project time management is the core function of project management whereby any changes in time will affect the success of the project.  Project time management includes the processes required to accomplish timely completion of the project.
One of the tools being used to achieve this objective is Project Scheduling. It is the tool that describes what work is to be done, who will undertake the work (resources) and when it should be done. It is the processes which enable better & more predictable outcomes and more effective use of limited resources.
 

The purpose of the project schedule is to provide a useful 'road map' that can be used by the project manager and the project team to:

• Plan, monitor, and control the timely execution of the work, from the day the project commences through each of its phases to successful completion
• Track and monitor the progress of the project
• Manage resources more smoothly
• Identify and monitor dependencies and constraints between tasks to avert preventable delays; and 
• Communicate more frequently and effectively with stakeholders.