as you already know, in Microsoft Project online or desktop version there are lot Task constraints (for example: Start No Earlier Than, Finish No Earlier Than, Must Start On, Must Finish On, etc.) In Microsoft Project for the Web you can find only two Task Constraints: Start No Earlier Than (SNET), and Finish No Earlier Than (FNET), and both of them are Semi Flexible Constraint type.
Let me show you those constraints. First (as always) I will create simple Project with three Tasks:
Let’s see how does it look at the Timeline View:
Now, I will put 5/14/2020 as Task 2 Start Date:
If I hoover my mouse over Strat Date I will see:
the little “star” in the right corner shows that it is constraint for the Start date. Now if I click on that date I will see:
here I can see “warning message” about constraint, and I can click on the button “Remove Constraint”, and it will be removed, so the Start Date will be set As Soon As Possible (know as flexible constraint). I will not do it for now.
Now I will set Finish date for Task 3 as 5/26/2020, and I will get:
As you can see Start date has been changed so duration remains 4 days!
Now I will change Duration for Task 1 to 1 day, and I will get:
As you can see Task 2 has the same Start Date, because it cannot be started before 5/14/2020.
I will change Duration for Task 2 to 1 day as well, and I will get:
As you can see Task 3 has the same finish Date, because it cannot be finished before 5/26/2020.
Finally I will change Duration for Task 1 to 10 days, and I will get:
Now, Start date for the Task 2, and finish Date for the Task 3 are changed, because those date are later than previous ones. And since they have No earlier constraint, it means that both of them can start and finish later.