Although the importance of JIT in improving companies’ operational performance is
recognized by several authors, conflicting opinions about the definition of JIT
implementation boundaries could be found in the literature. This research aims to analyze
different competing models about the relationships that can exist between the
implementation of JIT within companies’ boundaries (i.e. JIT production) and upstream
(JIT supply) and operational performance, and in particular test whether JIT supply acts
as a moderator in the relationship between JIT production and operational performance
(efficiency and delivery) and/or whether these practices are causally related
