I am fairly new to Asta Project Planner, I am troubled that the contractor has submitted a schedule indicating activities with remining durations indicate finish dates prior to the data date.

For example, one activity indicated a remaing duration of 10days; however, the activity was shown completing on September 27, 2017  or prior the progress date or data date of OCT 1, 2017.

I should note the activity finishing September 27, 2017 was also indicating -20 days float (however the completion date of the project was maintained). I am aware there is an option under reschedule (Negative Float Applies to Chain) to show this true status of the schedule which is behind schedule. 

However i am wordering why this option is available, it goes against everything i thought i knew about scheduling. It is also appears that the Contractor was not aware of this option and/or just didn't reveiw the update before submittal.

I dont recall seeing any discussions on the PP forum concering this issues so i would like to open it up for discussions.

Thanks

Dan