I will show you what happens when you link manually scheduled tasks and auto scheduled tasks in MS PROJECT 2010. First, I will enter four tasks in manually scheduled mode:
Now I will link them. I will make Task 1 as predecessor of Task 2, Task 2 as predecessor of Task 3, and Task 3 as predecessor of Task 4. I will get:
You can see that every task has 1 day duration. Now I will break the links (I will erase predecessor field) and I will get:
Duration, Start and End date remains same, but links are broken.
Now I will start all over again. I will put description in all task (in Duration field, and Start and End date field):
and I will link them in the same way I did before:
You can see that Task 1 and Task 3 has still unknown duration, but they have same start and end date. They have also question mark in Task mode field.
Task 2 and Task 4 has 1d (estimated) duration, and they also have Start and End date set by MS PROJECT 20101. Remarks in Start date and End date fields are overwritten.
Now I will have 4 Tasks but two of them will be in auto scheduled mode.
Task 1 and Task 3 has 1 day duration by default and Start date is same as the project start date. I put 02.06.11 as a Start date for Task 2 (manually scheduled) and 01.06.11 as a End date for Task 4 (manually scheduled). OK. Now I will link them as I did before and I will get:
You can see that Start date and End date field are overwritten for manually scheduled tasks and that they have 1 day duration now.
But, what if I really want 02.06.11 as a start date for Task 2? I will enter that date in Start date field and I’ll get:
Do you see red line below Start date for Task 2? Put the mouse on that field and you’ll get:
Now I will right click on that field and I will get:
If I click on Respect Links, MS PROJECT 2010 will overwrite Start date for Task 2:
If I click on Fix in Task Inspector instead I will get:
From Task Inspector you can choose Respect Links, and you will get the same result as I show you in previous picture or you can select Auto schedule and you will get:
Now, the Task 2 is in Auto scheduled mode.
From my point of view, be extremely cautious with manually scheduled tasks. Use auto schedule mode whenever you can! When you use auto scheduled mode you let the control to MS PROJECT 2010 and you are avoiding unpredictable results.
In my next blog I will show you how can you use manually scheduled task in (from my point of view) best way.