Are you using any software to manage this work schedule? How did you create this schedule? Manual schedule sheet is very tough to manage, better you can use any roster software. This allows to see the actual progress of your project plan and compare it with the original schedule. Recently, I found a great tool and started to use. It is Replicon's roster software which helps to manage my schedules. Here's the reference - http://www.replicon.com/olp/rostering-software.aspx