Statistical Process Control (SPC charts)
Demonstrate and explain how statistical process control charts SPC charts are created and how Westgard rules can be applied in your day to day environment.
You are now supplied with 2 sets of data based upon temperature measures in a fridge. Set 1. 20 data points – used to create an SPC chart.
Set 2. 50 Data points to plot on the chart created.Using the supplied 20 data points in set 1 calculate the mean and standard deviation. You are required to calculate the “Sample standard deviation” – s and not “Population standard deviation” – σ2. Once you have calculated these values use the mean and standard deviation values to calculate values for +/-1, 2 & 3SD.
3. These 20 data points have been obtained in the initial set-up of a fridge in your local area.
4. Using the calculated values create a statistical process control chart for monitoring the temperature of the fridge in routine operation.
5. If you are not confident about how to calculate these values or produce a statistical process control chart, use the Discussion forum for Activity 2.2, to gain assistance from your fellow students and the Tutor.
6. Once you have created your SPC chart you should plot the 50 data points from set 2 onto your chart.7.These data points simulate the temperature control in the fridge over the next 50 data points.
8.You are now required to apply the Westgard rules to your plotted data. Use only the base 6 rules from the Westgard multi rule.
9.Annotate your chart with your identified Westgard rule breaches.
Write a 1500 word report, of publishable standard, demonstrating your understanding of SPC charts, their use, why it is important to calculate your own control values, rather than manufacturer-supplied data and the application of the Westgard rules based on independent research. Within your report you should critically analyse the SPC chart produced above and discuss the identified failure points, suggesting reasons for the failure, action to be taken on the identification of the failure and what remedial or corrective actions may have been taken to bring the system back into control. Your report should contain your calculated data, including calculations/formulas used and why, base SPC chart and your annotated, plotted, chart. You should interpret the chart as if the data 10.points were being plotted in real time reading the chart from left to right as data is plotted.
11. Your report should also include how you would implement these techniques in your own area to benefit your department.
