This historical account of operations research at Bell Laboratories was drafted in the late 1970s when the authors were part of the Operations Research Center within Bell Laboratories at AT&T; it has not previously appeared in the open literature. We have added a few references to later publications that describe particular aspects of the period covered. Discussions of technological practices and organizational arrangements expressed in the present tense represent a viewpoint of about 1980, before “divestiture” split up the Bell System. The principal topics in this issue of Operations Research are the organizational history, and teletraffic theory and engineering. Upcoming issues of Operations Research will include parts II and III of this account, comprising capacity expansion in telephone networks, operations analysis, applied statistics, and related OR activities. A comprehensive table of contents for parts I, II, and III can be found in the Online Collection of the Operations Research Home Page, at www.informs.org/pubs .

This historical account of operations research at Bell Laboratories was drafted in the late 1970s when the authors were part of the Operations Research Center within Bell Laboratories at AT&T; it has not previously appeared in the open literature. We have added a few references to later publications that describe particular aspects of the period covered. Discussions of technological practices and organizational arrangements expressed in the present tense represent a viewpoint of about 1980, before “divestiture” split up the Bell System. A comprehensive table of contents for parts I, II, and III can be found in the Online Collection of the Operations Research Home Page, at www.informs.org/pubs . We describe the work done in the Bell System up to about 1980, mainly at Bell Labs, both in developing the techniques of operations research and in applying them to the telecommunications business. This account does not include military OR or direct support of other federal government activities. Part II covers capacity expansion and operations analysis.

This historical account of operations research at Bell Laboratories was drafted in the late 1970s when the authors were part of the Operations Research Center within Bell Laboratories at AT&T; it has not previously appeared in the open literature. We have added a few references to later publications that describe particular aspects of the period covered. Discussions of technological practices and organizational arrangements expressed in the present tense represent a viewpoint of about 1980, before “divestiture” split up the Bell System. A comprehensive table of contents for parts I, II, and III can be found in the Online Collection of the Operations Research Home Page, at http://or.pubs.informs.org .