Q: Why not just use biometrics? A good fingerprint reader doesn't really cost all that much. No passwords to forget - ever.
A Biometrics may be an answer for some enviroments but it is not a cover all, some examples are below
Factory users: may have gloves, dirty/greasy hands that means they cant authenticate that way (ours cant) Remote users over internet connections, i.e. on other poeples computers may not have an apropriate biometric reader
although Token authentication may be a way forward?