Outsourcing is one of the top priorities on the strategic agenda of origina
l equipment manufacturers (OEMs) in many industries. The decision of outsou
rcing an activity as opposed to doing it in-house and the development of a
part or parts system is one of the most complex decisions facing today's in
dustrial managers. Several models have been developed in order to aid in th
is process. The present paper analyses some of these models, and proposes a
n extension based on the role that specifications might play in outsourcing
decisions, Based on how the specification is generated and on the nature o
f the data it contains, it can be of significant help in outsourcing decisi
ons. The research reported in the paper is based on a longitudinal study of
one automotive OEM (global family), one truck OEM and four medium-sized ex
pert suppliers, all located in Europe. A procurement matrix is developed in
which guidance for outsourcing decisions is provided in terms of specifica
tion generator, type of supplier, and contract relationship. (C) 2000 Elsev
ier Science Ltd. All rights reserved.