Describe a situation in which a weak but easy-to-use password may be adequate?

In a typical office, biometric authentication might be used to control access to

employees and registered visitors only. We know the system will have some false

negatives, some employees falsely denied access, so we need a human override,

someone who can examine the employee and allow access in spite of the failed

authentication. Thus, we need a human guard at the door to handle problems as well

as the authentication device; without biometrics, we would have had just the guard.

Consequently, we have the same number of personnel with or without biometrics, plus

we have the added cost to acquire and maintain the biometrics system. Explain the

security advantage in this situation that justifies the extra expense

Please use own words