Thanks but I solved it by creating a 24-7 calendar and assigning it to the activity. That way activities that don't depend upon resourcing such as concrete curing, filling a reservoir with water, emptying a tank, drying out a newly insulated furnace etc. can be calculated using the correct duration.
In MS Project durations for activities which are not resource dependent (such as preheating a furnace) can be entered as 'e' days(6e). How we do it in Suretrak or P3?
