I spent all day and still no lock or door......
do I keep trying or stop wasting my time.
I've tried several times from both sides of the doorway ,and still failed.
please let me know what I'm doing wrong.
The equations are posted on the Locks and Keys rules page so you can plug in your stats and the door type to determine your chance of success. You might be trying to upgrade a door that is too difficult for your skill level to handle. Either way, you can determine your success chance and use that to decide if you think it's worth continuing to try.
If you mean that's what the equation tells you, that would be a percentage, and not the number of tries. There is no specific number, since it's chance.