Statistical Process Control - Admission/Application Essay Example

The time will vary from around 18 minutes to 33.5 as long as the process stays in control, due to the normal variation in the process. Hence, another function of control charts is to approximate the process average. Secondly, control charts help to estimate the variation (the spread in the histogram). Since a calculated average or standard deviation has no significance unless the process that generated it is in statistical control. The average for the chart above with the special cause of variation was 27.

7 minutes compared with an average of 25.8 devoid of the particular cause, about a 7 percent difference. Assuming for another two weeks, instead of waking up your normal time, you wake up earlier and leave the house 30 minutes earlier. You will be getting to work 30 minutes earlier than the previous days. This will result in a change to the control chart as shown below. The new chart displays a run below the average, a clear indication that leaving home earlier has decreased the time it takes to get to the office.

The mere fact that you are able to arrive in the office earlier than you normally do, has significant influence on the control chart. The control limits may now be re-examined to show the current average and new data variation. The resulting control chart will look like this: Thirdly, control charts can be used to judge the effect of your process improvement efforts. In the example provided, the process alterations worked resulting into new control limits and the process can be monitored into the future any significant causes.

It is undoubtedly true that no complete process can deliver perfect outputs all the time. There will always be outputs that deviate from the normal expected results. Generally, this means there will be a few errors even though the outcome will still be meaningful. However, whenever the variation is insignificant, the more effective the process.   Common Cause variation also known as