I'm having trouble understanding the way assigning resources impact on durations of tasks. For example, let's say I have already created a calendar with non default working time of 9.5 hours per day: 7.30am-12pm and 1pm-6pm. I have also entered the duration option that 9.5 hours = 1 day.
I create a task which by default has 9.5 hours entered in the work column and 1 day entered in the duration column. The start time is 7.30am and finish time is 6pm, which is what I would expect.
Then I create a materials resouce (bag of cement). If I assign that resource to the task I created previously, the value in the work column changes to zero and the finish time changes to 9.30am the following day.
Why does this happen?