INTRODUCTION
A Strategy Administrator may wish to update the minimum password requirements for environments that use standard authentication (username and password). These options can be accessed from the Strategy Intelligence Server Configuration screen in Developer:

However, changing these requirements will not update or change any existing user passwords. If a user password no longer meets the new minimum requirements, what happens when they attempt to log in?
RESULTS
If a user attempts to log in with an old password that does not meet the minimum requirements, they will successfully log in. Their existing password will continue to be valid until they attempt to change their password. At that time they will need to create a new password that meets the updated minimum requirements.
A user can be forced to update their password by marking the appropriate checkbox on their user page in Developer:

This checkbox can be marked for all users easily, via Strategy Command Manager:
ALTER USERS IN USER GROUP "Everyone" CHANGEPWD TRUE;