Locking mechanisms are very important, they are designed to create a secure access controlled environment. As technology progresses these high level locking mechanisms assists you extend your system’s framework and comply with your organization’s security requirements.

Keeping the purpose central, one can decide which mechanism suits best and meets the requisite.

Fail-Safe:

In the fail-safe mode, when the power is supplied the lock sets to locked state whereas, on power failure, the door automatically unlocks, allowing people to exit the area. The fail-safe locks are widely used in places where the safety of life is a priority. However, the main drawback with this mechanism is that once the power supply is cut, there should be another way to secure all the entry and exit points.
EM (Electromagnetic) locks is great example of fail-safe locks.

Fail-Secure:

Fail secure locks use a mechanism known as electric latch retraction (EL), where, the latch remains in retracted position as long as power is applied. Once, the power supply is cut, latch sticks out again, locking the door. The main drawback with the mechanism is the lockout condition in case of a prolonged power cut. In the scenario, there has to be a provision for either a mechanical bypass or an external power terminal. An example of a fail-secure lock is the powered latch lock.

If your association is looking for securing an area where people are expected to assemble, for instance, office gathering rooms, operational regions, regular regions, cafeteria and so on fail-safe mechanism is the correct alternative. While, if you are looking for a solution to secure your significant resources, for example, extra spaces, worker rooms, bank storage spaces, fundamental doors, main entrances, etc., then fail secure is the way to go.
It is always advisable to let an expert have a look and design a solution for you incorporating whichever technology serves your needs in the best way.

It is always good to have a specialist to survey and design the mechanism that suits your need.