Combining 2 duration columns to get one Finish date

MSprojecthelpme 

Well, it will report that plumbing was starting 10 days later but that's Start Variance, not Duration Variance.

Sorry but you can't add something to the finish date without increasing the Duration field, unless you also change the Start field. Duration is the difference in working days between the start of a task and the finish of a task, unless there is a split, then task duration only tracks the scheduled working days where the span of the split is excluded. For example, in the screen shot below, framing for building one was going along swimmingly for the first three days, then over the weekend a storm blew in and delayed further framing for 3 days. That 3 days is entered into a custom Duration field (Duration1 renamed as "Delays") and a split is applied to the framing task. Note the task Duration field still shows the original 20 days but the split delay shifted the schedule to the right by those 3 long rainy wet days (yuck). If other delays occur, additional splits can be applied. The advantage here is the the delay is graphically very apparent but you could, as Dale suggested, make an entry in the Task Notes field why the split occurred.

So how do you do a split? It can be done manually via Task > Schedule group > Split task icon and then hovering your mouse over the start of the split and pulling it over the 3 days. Or, it could be done programmatically with VBA, enter the delay, run the macro and boom! there it is.

Is you head spinning yet?

John