Auto schedule problem with MS Project 2010

Question

I am setting up a project in 2010; I have tasks, subtasks, predecessors but no resources assigned.

I have a task dependency that should start April 3 based on the predecessor finishing April 2. There is a separate tasks' subtask that has the main task as a predecessor. The dependency is finish to start, which means when the predecessor task finishes, the new task can start. The predecessor task is scheduled to finish July 14; the dependent task keeps auto scheduling to July 13! I cannot figure out what the problem is, and it is driving me nuts!

Answer 1

Do you have a must finish on constraint on the succeeding subtask and is that subtask fixed duration? If so, that would cause the subtask to start a day early to protect the must finish on constraint, which produces a negative slack between the two related tasks.

Answer 2

You lost me on the April then July dates - are they the same tasks? Check for Actual start dates on the tasks - display the Tracking table. No lead on the F to S link?

Answer 3

If you need it to and nothing else works, and it's only this one subtask causing the issue set the predecessor to the task as (TaskID)FS+1d and that will add a lag.

ie. if the row is 14 then 13FS+1d

It's not ideal but it will give you what you need.