Quality Management Tools & Techniques - Assignment Example

By visually observing the histogram, it is possible to determine whether or not the process is in control. In this paper, the capability analysis for individual variables is applied using Minitab. This analysis yields a process capability report even when the data for the variables are not normally distributed. In this case, the manufacturing process produces a single hard drive using three distinct processes, hence the application of this method is suitable in order to evaluate each process independently.

As such, histograms of the data for each process will be generated, which will help to verify whether or not the processes are in control. In this case, three main measures will be used to evaluate the capabilities of the three processes including Cp, Cpk and PPM. The measure Cp is an index that measures potential capability of a process; that is, the capability of a process in meeting certain conditions. For a capable process, Cp should be greater than one. The measure Cpk, on the other hand, is a measure of whether or not the process is conforming to the required specifications (Bass, 2007).

For a perfectly centered process, Cpk should be equal to Cp. The measure PPM (parts per million) represents the number of defectives in every one million parts manufactured. By visually observing figure 1, the data is not normally distributed. Indeed, the data seems to be both bimodal and right-skewed. However, the data values are within the specified limits. The value of Cp = 1.41 is greater than one, which indicates that the process is capable. Additionally, the value of Cpk = 1.30 is almost equal to that of Cp hence the process is centered.

On the overall performance, for every one million hard drives produced by the manufacturer, 18.29 parts will exceed the specified limits on the lower specification limit (LSL) side while 238.83 parts will exceed the limit on the upper