We also assign journals by subject field and have general accounts for
titles of faculty-wide interest.  However we also allow costs to be
shared between/amongst faculties where appropriate.  Decisions about
cancellation are taken in conjunction with teaching departments and are
then advertised university-wide - if there is sufficient objection then
the journal will be continued but possibly re-assigned to a different
department/faculty.  I'm sure this is common practice.
Liz Stevenson
Edinburgh University Library