The quality of the service relys on the fact
that relationships between the ID and the
associated location(s)
of the object (in Internet context, URL) are up-to-date
Relevant questions are:
How to maintain these relationships
(mappings)?
How to make updating of mappings between
location and identifier
low cost and reliable?
How to guarantee such a service in the long
term?
(In Internet
based digital library environment PID > URL,
in physical
library environment PID > shelf mark)