Logic driven by Early Dates

yes you can go to tools schedule then options and change the 2 setting there half way down the page where it says When scheduling progressed activities select use actual dates and under that where it says calculate start to start lag from and change this to actual dates. 

Hi Zoltan, 

I've used this change before and it worked however it isn't working today on a different schedule. Could there be a reason for that? I've tried changing it back and forth a couple of times now with no impact. I'd like the logic to be driven by the forecast dates not the early dates. 

Also, what can have an impact on the early dates? They seem to change when the project is scheduled?

Thanks

changing this setting should work everytime.

The Early Dates will ALWAYS change when the project is scheduled this is the whole point of scheduling.

the Early date are derived from the froward pass this is the earliest an activity can start and or finish based on progress todate, logic and any constraints.

The forward pass begins at the data date and goes forward in time and calculates the earliest dates that an activity can start and or finish based on progress todate, logic and any constraints.

The backward pass begins at the project must fininsh by date or the last activity if it has a constraint date and it goes backwards  in time and calculates the latest dates that an activity can start and or finish based on progress todate, logic and any constraints.

The difference between the late date and the early date is the totla float.

This is the basis of ALL cpm scheduling once you understand this the rest is easy. 

Hi Zoltan, 

Once I found the correct setting in Schedule > Options it worked fine. 

Thanks again

glad I could help