Sampling Plan for Process Average Based on the Modeling of the Process Output in a Local Manufacturing Enterprise

Abstract

In today’s competitive market and to ensure manufactured goods meet the internationally recognized average quantity system, manufacturers must begin to put in place sampling plans to monitor the average net weight of goods in lots released into the market. In this study, we deployed the use of the X bar-S chart to investigate process stability and the continuous probability distribution plots to model the process output and obtain process parameters useful in the design of an economic process average sampling plan. The UCL and LSL are deployed as two key locations in the design process. This plan gives a lot-by-lot average net weight sampling plan requiring a sample size of 16 per lot, and an average acceptance limit of 70.2g. This paper demonstrates how the design of a process average sampling plan can be hinged on the existing process parameters, especially when the process is found to be stable, however slightly off-centered the process might be, as no manufacturing process can be entirely free from errors. This is an easy-to-use sampling plan that does not require much training to be implemented on the factory floor by artisans and foremen.