In the pre-PMBOK 6 World, Schedule Management was known as Time Management. Managing Schedules and meeting deadlines is what most people think of when they think about the role of a Project Manager. The PM role is obviously much more than just meeting deadlines. Infact, even Schedule Management is much more than meeting deadlines!
Schedule Management involves breaking down the project work into activities. These activities are then placed in a logical order and estimated so that a realistic project schedule can be developed.
Below is a snapshot of where all the processes of the Schedule Management Knowledge Area belong,

Plan Schedule Management provides guidance throughout the schedule management knowledge area. This is where you define all the processes you will use to plan and control the project schedule
Define Activities is where the work packages (remember WBS?) are broken down into activities. These activities are later used for estimating, scheduling, network diagrams and other fancy stuff!
Sequence Activities is where the activities are placed in a logical order. Yes, this is where the network diagram is created and half the battle is won!
Remember, we are yet to come up with the time it will take to complete the project. Estimate Activity Durations is where you estimate the time it will take to complete each activity
Making use of the outputs of previous processes like durations and resources, you create a schedule in the Develop Schedule process
Control Schedule, just like Control Scope, is a process designed to monitor and control the project schedule. This ensures that the schedule is kept up to date
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