The explanation given by PMBOK5 is as follows:
A logical relationship in which a successor activity cannot finish until a predecessor
activity has started.
Example: The first security guard shift (successor) cannot finish until the second
security guard shift (predecessor) starts.
Imagine you have to do a 2 days of Treatment on the wall which should finish 24 hours before starting painting. Here Painting – although happening later – is the Predecessor (main activity and Treatment is the Successor (Secondary) activity. In this example, the successor activity will finish 24 hours before the Predecessor activity starts. So PMBOK5 explanation is incorrect.
In SF relationship, the start of Predecessor (main) activity, DECIDES the finishing of Successor (secondary) activity, with a suitable lead or lag as required.
Does anyone agree with this definition?