Librarians have been concerned about stated publication patterns not
matching actual production for many years. I refer you to this article
published by Haworth Press.  Unfortunately it has not been digitized yet so
you'll need to consult the printed journal.

K.C.Garg and R.K. Dua "A plea for the rationalizing of the publication
schedules of periodicals," Serials Librarian 9, no. 4 (1985): p.89-97.

I'll quote the abstract:

This paper describes various types of publication schedule of periodicals,
and points out problems caused for librarians by inconsistency and
unpredictable publication schedules. Suggestions are made concerning the
standardizing of publication schedules.
********************************

Let me cast my memory back to 1985.  I think there were maybe 1 or 2 check
in systems that had any sort of predicative check in module. OCLC's Serials
Control Subsystem did, since I had used it. I am not sure if Faxon's
MicroLinx was out then or if their SC10 product had it. So we were mainly
talking about manual check in.

Amazing how these nagging issues never seem to completely resolve
themselves. Of course, we don't exactly live in a perfect world either.

Susan

Susan Davis
Head, Electronic Periodicals Management Department
University at Buffalo (SUNY)
134 Lockwood Library
Buffalo, NY  14260-2210
(716) 645-2784
(716) 645-5955 fax
unlsdb@buffalo.edu