Research output: Contribution to book/anthology/report/proceeding › Article in proceedings › Research › peer-review
As simple as possible but no simpler : An inquiry into approximations for a re-order point inventory control model with gamma-distributed demand. / Thorstenson, Anders.
2018 IEEE International Conference on Industrial Engineering and Engineering Management (IEEM). New York, NY : IEEE, 2018. p. 153-157 8607312.Research output: Contribution to book/anthology/report/proceeding › Article in proceedings › Research › peer-review
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TY - GEN
T1 - As simple as possible but no simpler
AU - Thorstenson, Anders
PY - 2018
Y1 - 2018
N2 - The basic single item, continuous review, reorder point inventory control model with given order quantities and a fixed lead time is considered. The objective is to minimize inventory holding cost for the safety stock by determining the reorder point subject to a fill-rate constraint. Several approximations have been suggested for this model. Many of them assume that demand during the lead time follows a normal distribution. In this paper, model approximations assuming normal distributions are contrasted with gamma distributed lead-time demand. It is confirmed numerically, that the simplest approximation is quite accurate under some fairly restrictive conditions. However, it is found that considerable errors can be expected when demand uncertainty is increased, especially when the gamma distribution is applied. Fortunately, the more precise model specification with only marginally increased complexity works quite well, also for the gamma distribution.
AB - The basic single item, continuous review, reorder point inventory control model with given order quantities and a fixed lead time is considered. The objective is to minimize inventory holding cost for the safety stock by determining the reorder point subject to a fill-rate constraint. Several approximations have been suggested for this model. Many of them assume that demand during the lead time follows a normal distribution. In this paper, model approximations assuming normal distributions are contrasted with gamma distributed lead-time demand. It is confirmed numerically, that the simplest approximation is quite accurate under some fairly restrictive conditions. However, it is found that considerable errors can be expected when demand uncertainty is increased, especially when the gamma distribution is applied. Fortunately, the more precise model specification with only marginally increased complexity works quite well, also for the gamma distribution.
KW - Backordering
KW - continuous review
KW - fill rate
KW - gamma distribution
KW - normal distribution
KW - safety stock
KW - stochastic demand
UR - http://www.scopus.com/inward/record.url?scp=85061776354&partnerID=8YFLogxK
U2 - 10.1109/IEEM.2018.8607312
DO - 10.1109/IEEM.2018.8607312
M3 - Article in proceedings
SN - 978-1-5386-6785-9
SP - 153
EP - 157
BT - 2018 IEEE International Conference on Industrial Engineering and Engineering Management (IEEM)
PB - IEEE
CY - New York, NY
Y2 - 16 December 2018 through 19 December 2018
ER -