Activity Network

One of the 'second seven tools', this is a classic project planning tool for piecing together a multi-task complex set of interdependent activities. It allows you to calculate what task starts when, what float there is in the project, etc.

Also called an 'Activity-on-Node Diagram', the alternative (but potentially more troublesome) method of doing this is with an 'Activity-on-Arrow Diagram', or simply 'Arrow Diagram'.