From study last installation main contribution of water leakage is Flashing -
I make a simple calculation for flashing to fit the base on measurement of roof profile
Detail of roof profile play a very big part in deciding Flashing, if fail in making good flashing
Will end up in leaking .
Refer to attachment.
Follow the instruction , maybe is not perfect and some area might not accurate
But at least to simplify the calculation job.
Any area that you think need to improve please inform me.
Maybe we can use for Next installation.