Examine the following p chart for defective calculator batteri...

Question

Examine the following p chart for defective calculator batteries and briefly describe the action that should be taken.

P chart showing proportions of defective calculator batteries with upper and lower control limits marked.

Accepted Answer

Hello, everyone. Let's take a look at this question together. Review the following P chart, which represents the proportion of defective light bulbs in a manufacturing process. Based on the chart, what necessary actions should be taken. And here we have our P chart for defective light bulbs. Is it answer choice A, Investigate the cause of the out of control points and identify special causes of variation. Answer choice B, ignore the out of control points, as they are likely random fluctuations. Answer choice C, shut down the production process immediately, and replace all machinery, or answer choice D, the process is statistically in control and does not require any immediate action. So in order to solve this question, we have to recall what we have learned about reviewing a chart. Determine based on this chart what necessary actions should be taken. And so the first step is to analyze the chart and determine if the chart is out of statistical control, which we do so by analyzing the chart based on the three standard out of control criteria, where the first criteria is if there are any points outside of the control limits. The second criteria is a run of consecutive points on one side of the center line, and the third criteria is a trend of increasing or decreasing values over several points. And so the first step is to determine if there are any points outside of the control limits, which we know that we have our upper control limit, which is the red dashed line, and our lower control limit, which is the blue. line and our center line is the green dashed line. And based on this information, we can identify that there are, in fact, a few points that are above and below the control limits, as we have 2 points that exceed the upper control limit and 2 points that fall below the lower control limit. So we have points outside of the control limits telling us this process is out of statistical control. Next, we check for a run of consecutive points on one side of the center line, such as 8 or more consecutive points above or below the center line. However, from our control chart, we do not see 8 or more consecutive points above or below the center line, so we do not meet the criteria for the second standard. And lastly, the third standard of out of control criteria is a trend of increasing or decreasing values over several points, such as a consistent upward or downward trend. However, from our control chart, we do not see a consistent upward or downward. trend, so we do not meet this criteria, and we only meet the criteria for the points that are outside of the control limits. And based on this information, we know that the points that exceed the upper control limit suggest a higher than expected defect rate in those batches. And the points that fall below the lower control limit could indicate an unexpected variation in the process, possibly due to measurement errors or an unusually good batch, and based on this information, we know the necessary actions that should be taken include investigating the causes of the out of control points to determine. If there are issues with raw materials, machine calibration, or operator errors, as well as identify and eliminate special causes that might have led to excessive variation in defect rates, monitor future batches closely to ensure the process returns to a state of statistical control, and lastly, we can consider process improvement. To maintain consistency in defect rates and ensure compliance with quality standards. So looking at our answer choices, we can identify that the necessary action that should be taken is answer choice A, as answer choice A says, to investigate the cause of the out of control points and identify special causes of variation. Which is a necessary action that should be taken based on this P chart for defective light bulbs, and all other answer choices are incorrect. I hope you found this video to be helpful. Thank you and goodbye.

Examine the following p chart for defective calculator batteries and briefly describe the action that should be taken.

Key Concepts

P Chart

Control Limits

Action Plan

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