The only thing that a business or other organization can do to be prepared for bomb threats is to have good plans for what to do if such a threat occurs.
It is impossible for a business to do much to prevent bomb threats from occurring. A company can, of course, have good security that attempts to limit access to its facilities. However, it cannot stop people from calling on the telephone and claiming that they have planted a bomb.
The only thing that the organization can really do is to have procedures in place. The organization needs to have a plan for determining how serious the bomb threat is. It does not want to simply evacuate the facility, causing major disruptions, if the call is clearly a fake. However, it also does not want to ignore a threat, only to have it be true. The organization then needs to have a plan for what to do when a bomb threat is determined to be credible. It needs to have a clear plan that allows everyone to evacuate safely. It needs to practice implementing this plan so that it can put the plan into action in case of a real bomb threat.