Monitoring processes through inventory and manufacturing lead time

View/ Open
Issue date
2015-06Author
Cuatrecasas Arbós, Lluís
Fortuny Santos, Jordi
Ruiz de Arbulo López, Patxi
Suggested citation
Cuatrecasas Arbós, Lluís;
Fortuny Santos, Jordi;
Ruiz de Arbulo López, Patxi;
Vintró Sánchez, Carla;
.
(2015)
.
Monitoring processes through inventory and manufacturing lead time.
Industrial management and data systems, 2015, vol. 115, núm. 5, p. 951-970.
https://doi.org/10.1108/IMDS-12-2014-0375.
Metadata
Show full item recordAbstract
Purpose – Since lean manufacturing considers that “Inventory is evil”, the purpose of this paper is to
find and quantify the relations between work-in-process inventory (WIP), manufacturing lead time
(LT) and the operational variables they depend upon. Such relations provide guidelines and
performance indicators in process management.
Design/methodology/approach – The authors develop equations to analyse how, in discrete
deterministic serial batch processes, WIP and LT depend on parameters like performance time (of each
workstation) and batch size. The authors extend those relations to processes with different lots and the
authors create a multiple-lot box score.
Findings – In this paper, the relations among WIP, LT and the parameters they depend on are
derived. Such relations show that when WIP increases, LT increases too, and vice versa, and the
parameters they depend on. Finally, these relations provide a framework for WIP reduction and
manufacturing LT reduction and agree with the empirical principles of lean manufacturing.
Research limitations/implications – Quantitative results are only exact for discrete deterministic
batch processes without any delays. Expected results might not be achieved in real manufacturing
environments. However, qualitative results show the underlying relations amongst variables. Different
expressions might be derived for other situations.
Practical implications – Understanding the relations between manufacturing variables allows
operations managers better design, implement and control manufacturing processes. The box score,
implemented on a spreadsheet, allows testing the effect of changes in different operational parameters
on the manufacturing LT, total machine wait time and total lot queue time.
Originality/value – The paper presents a discussion about process performance based on the mutual
influence between WIP and LT and other variables. The relation is quantified for the discrete
deterministic case, complementing the models that exist in the literature. The box score allows
mapping more complex processes.
Is part of
Industrial management and data systems, 2015, vol. 115, núm. 5, p. 951-970European research projects
Collections
The following license files are associated with this item: