Probability Distribution of Leadtime Demand,
Abstract
This study examines 11 probability distributions to determine which distribution best describes demand during leadtime for 1H Congnizance Symbol (Cog) material. Proper selection of the distribution is criteria in the accurate calculation of reorder levels. Actual leadtime demand observations were calculated in the study. Histograms, a chi-square goodness-of-fit test and a Mean Square Error measure were used to analyze the leadtime demand data. Histograms of the data suggested the following distributions to describe leadtime demand: Exponential, Gamma, Bernoulli-Exponential, Poisson, Negative Binomial and Geometric. The chi-square goodness-of-fit test indicated that none of these distributions fit the computed leadtime demand data across the entire range of the distribution. However, a relative test of the right hand tails of the distributions, which are most critical in determining reorder levels, indicated that the Bernoulli-Exponential provided the best relative fit for 1H Cog items. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 29, 1984
- Accession Number
- ADA144952
Entities
People
- A. P. Urban
- G. Evans
- J. A. Mellinger