Quality Management Mc1591 Quiz 2

Explanation
Cp is not a control chart. Control charts are used to monitor and control processes by plotting data points and analyzing them for any patterns or trends. Cp, on the other hand, is a capability index that measures how well a process is able to meet specifications. It is not used for monitoring or control purposes like control charts are.

Explanation
Process control is carried out during production to ensure that the manufacturing process is running smoothly and meeting the desired quality standards. It involves monitoring and adjusting various parameters such as temperature, pressure, and flow rates to maintain consistent product quality and minimize defects. This helps in identifying and rectifying any issues or deviations in real-time, preventing the production of faulty or substandard products. Therefore, process control during production is crucial for maintaining efficiency, reducing waste, and ensuring the final product meets the required specifications.

Explanation
High cost, low volume items typically require intensive inspection because of their high value and limited quantity. These items are often critical to the operation or success of a business, and any defects or errors can result in significant financial losses. Therefore, a thorough and detailed inspection is necessary to ensure that these items meet the required quality standards and specifications. This level of inspection helps to minimize the risk of defects and ensures that the high cost, low volume items are of the highest possible quality before they are delivered to customers or used in the production process.

Explanation
The correct answer is 99.7 because in a normal distribution, approximately 99.7% of the data falls within 3 standard deviations of the mean. This means that the percent of the sample means that fall within this range is also 99.7%.

Explanation
A range chart is used to monitor variables in a process. It displays the range of variation in a process over time, showing the difference between the highest and lowest values. By monitoring the range, it helps to identify any shifts or trends in the process, indicating whether it is stable or not. This chart is particularly useful when the process is not capable of producing consistent results within a specified range. Therefore, the range chart is the correct answer in this case.

Explanation
The p-chart is a statistical control chart used to monitor the proportion of nonconforming items in a sample. It is commonly used when the data being monitored can be categorized into either conforming or nonconforming. The p-chart helps to determine if a process is stable and within control limits, or if there are any special causes of variation present. It is a useful tool for quality control and process improvement.

Explanation
The mean chart is used to monitor the central tendency of a process. It tracks the average value of a process over time and helps identify any shifts or trends in the process mean. By plotting the sample means on the chart, it provides a visual representation of how the process is performing in terms of its central tendency. This allows for early detection of any deviations from the target value and facilitates timely corrective actions to maintain process stability.

Explanation
The p-chart is used to monitor the fraction of defective items in a sample. It is particularly useful when the sample size varies or when the underlying process is not stable. The p-chart plots the proportion of defective items in each sample over time, allowing for the detection of any shifts or trends in the process. By comparing the observed proportions to control limits, the p-chart helps identify when the process is out of control and action needs to be taken to improve quality.

Explanation
The control chart used for the number of defects per unit is the c-chart. This chart is used to monitor the count of defects in a fixed sample size, where the sample size may vary. It is particularly useful when the number of defects per unit can vary significantly. The c-chart helps to identify any patterns or trends in the defect count, allowing for timely corrective actions to be taken when necessary.

Explanation
The process capability is calculated by taking the difference between the upper specification limit (USL) and the lower specification limit (LSL), and dividing it by six times the standard deviation (σ) of the process. This formula ensures that the process capability index takes into account the variability of the process, as represented by the standard deviation. By dividing by six times the standard deviation, the process capability index accounts for the spread of data within six standard deviations of the mean, which is a common measure used in statistical process control.