Do you know what the weakest spot in your security is?
Whether you have a firm answer or not, chances are criminals could probably recognize it fairly quickly. When they do, they'll go along a path of least resistance to exploit it.
Even if you have strong jewelry store security, criminals can get creative and use trickery to commit their crimes. Theft is a common tactic, but robberies and burglaries can also occur if your procedures become careless.