Updating schedule

updating a schedule is when you apply progress to your schedule thru a certain date. An activity can be in one of three stages

not started

started (but not finished) = in progress

or finished - completed 

What you do is indicate any activities that have started recored the actual date they have started. If they are not finished you input the remaing duration for the activity to complete = in progress

You also record any activities that were previously started and have now finished and you indicate the actual finish date.

You also recored any activities that have started AND completed during the reporting period and indicate theri actual start and finish dates

You would also add any new work or change order work that ws issued to you. 

You then chnage the data date (PROGRESS THRU DATE) and recalculate the schedule.

The purpose of this is show where you are on your project either being on schedule, ahead of schedule or behind schedule. 

Zoltan's comments below are structurally correct, but there is more to updating than simply processing information.  This paper from 2002 is still current: Managing for success - the power of regular updates: http://www.mosaicprojects.com.au/PDF_Papers/P002_MFS_Full.pdf 

For more on the overall process of developing and maintaing a 'good schedule' see: http://www.mosaicprojects.com.au/PDF/Good_Scheduling_Practice.pdf 

For cost loaded schedules please take a look at the following reference.

http://www.nflaace.org/index_files/john_orr_cost_loaded_schedule_updating_pdf.pdf

While Patrick's references may be helpful the links do not work. I have stated the basic concept.