A schedule was built completely by my colleague, and after it was sent to the owner for approval, It was requested to modify it and divide all activities to more detailed ones with maximum duration 21 day.
I started to modify and divide these activities and merge some electromechanical items in the schedule, but I noticed that the finish dates for most activities when I run the schedule changed and pushed one day.
So I tried to reduce the durations for some activities and remain the others to make all finish dates as before and sent it back to the owner for approval.
Unfortunately, the owner disapproved it again and I started to modify it again and the finish dates for most activities when I run the schedule changed and pushed one day again.
Please Can any one guide me to discover the reason????