How do we calculate the latest finish time of a task?

Question

What is the formula to calculate the latest finish time of a certain task on the critical path? Please also provide a simple example (assuming there is a scientific method to calculate the latest finish time).

Answer 1

The Latest Finish Time (LFT), is the maximum time by which a task can finish without adversely affecting the project schedule.

The latest finish time is not really calculated, all you have to do is to look at the tasks following the task that you want to get its latest finish time, and get the task (from the following tasks) that has the smallest Latest Start Time (LST)

So LFT(task a) = minimum LST of all tasks following task a

Of course, all the tasks above must be on the critical path.