login/fails_to_user_lock is a SAP Parameter attribute which is used to control Number of invalid login attempts until user lock information. This is available within R/3 SAP systems depending on the version and release level.
Below is the standard documentation available and a few details of the attributes values .
Every time an incorrect logon password is entered, the failed logon
counter for the relevant user master record is increased. The logon
attempts can be logged in the Security Audit Log. If the limit specified
by this parameter is exceeded, the relevant user is locked. This process
is also logged in Syslog.
The lock is no longer valid after the current day is over. (Exception:
see login/failed_user_auto_unlock)
The failed logon counter is reset once the user logs on using the
correct password. Logons that are not password-based do not have any
effect on the failed logon counter. However, active logon locks are
checked for every logon.
See SAP Parameter Documentation for full SAP documentation for this profile parameter.