Certified Production & Operations Manager (POM) Practice Exam

The ideal weight of jars of pickles must be controlled. Which charts should be used together to monitor the weight?

1. c-chart only

2. R-chart only

3. x-bar chart and R-chart

4. p-chart and c-chart

The correct answer is: x-bar chart and R-chart

To control the ideal weight of jars of pickles, using an x-bar chart in conjunction with an R-chart is highly effective due to the nature of the measurement being taken. The x-bar chart is specifically designed for monitoring the mean values of a subgroup, allowing a manager to detect changes in the average weight of the jars over time. This is crucial for ensuring that the overall process remains stable and that the average weight remains within specified limits. The R-chart, on the other hand, provides an insight into the variability of the weights within each subgroup. It helps in identifying any changes in process variability, signaling whether the production process is consistent or if there is an increase in deviations from the mean. By using both charts together, one can effectively monitor not just the average weight but also the consistency of that weight across multiple production batches. This dual approach allows for comprehensive oversight of the production process, ensuring that both the average and variability of weights are kept under control, which is essential in maintaining product quality. The combination of these charts gives a complete picture of the process performance concerning the weight of the jars of pickles.