Watson John W, Moliver Nina, Gossett Kenneth
Northcentral University, Prescott Valley, AZ, USA.
J Pharm Technol. 2014 Oct;30(5):151-158. doi: 10.1177/8755122514534073. Epub 2014 Apr 29.
Current inventory theory is based on simulated data and unrealistic formulae. Inventory replenishment processes are therefore commonly disrupted, and out-of-stock (OOS) events are unnecessarily frequent. OOS events at a large-volume, long-term care pharmacy in North Carolina were compared among 4 sequentially applied methods of inventory control: () a manual system without Six Sigma protocol, () a manual system with Six Sigma protocol, () a computer-assisted system with Six Sigma protocol, and () an automated system with Six Sigma protocol. Daily OOS rates were recorded for 11 weeks during the implementation of each method. Between-group comparisons were performed, and time-series analyses were conducted during each implementation to determine the significance of the change in OOS rates over the evaluation period. In terms of the 2 manual systems, OOS rates were lower for the system to which a Six Sigma protocol was applied. In terms of the 3 Six Sigma systems, ranked differences were significant. The computer-assisted system had a lower OOS rate than did the automated system, and the automated system had a lower OOS rate than did the manual Six Sigma system. OOS rates were significantly reduced over an 11-week period for the computer-assisted and the automated systems. Six Sigma was found to be an effective process improvement strategy in the selected pharmacy setting. The study was the first inventory analysis performed with OOS events used as an empirical measure, in contrast to the simulated data used in prior studies.
当前的库存理论基于模拟数据和不切实际的公式。因此，库存补货流程常常受到干扰，缺货（OOS）事件频繁发生且毫无必要。在北卡罗来纳州一家大批量、长期护理药房，对四种依次应用的库存控制方法进行了缺货事件比较：（1）无六西格玛协议的手动系统，（2）有六西格玛协议的手动系统，（3）有六西格玛协议的计算机辅助系统，以及（4）有六西格玛协议的自动化系统。在每种方法实施期间，记录了11周的每日缺货率。进行了组间比较，并在每次实施期间进行了时间序列分析，以确定评估期内缺货率变化的显著性。就两种手动系统而言，应用了六西格玛协议的系统缺货率较低。就三种六西格玛系统而言，排名差异显著。计算机辅助系统的缺货率低于自动化系统，自动化系统的缺货率低于手动六西格玛系统。计算机辅助系统和自动化系统在11周内缺货率显著降低。研究发现，在选定的药房环境中，六西格玛是一种有效的流程改进策略。与之前研究中使用的模拟数据不同，该研究是首次以缺货事件作为实证指标进行的库存分析。
