Gantt+chart

A Gantt chart is used to plan and see the progress of a project with multiple steps that must be done simultaneously

Above is a Gantt chart taken from Wikipedia, we can see that Activities A and B Start at the same time, C and D can only begin once B has been finished. Progress can only be seen on the chart, they allow you to see how behind you are in the example above they approximately 30% behind schedule with Activity D far behind schedule.