A cookie company has collected the following data. They have a process that bakes and packages 11oz packages of cookies (the package says 11oz. but the true average may be a little off). They take a sample of 30 packages every two hours and have collected both the average net weight from each sample as well as the range of individual package weights over the last 7 shifts (28 observations). As flour is the predominant ingredient for this type of cookie, the supplier of the flour used when each sample was taken is also provided. They use two major suppliers. Acme is the primary supplier while Baker is currently used as a backup. While both are fairly reliable, the cookie company uses Baker as leverage in keeping Acme's price as low as possible.

Sample (shift # . sample #)	Avg. Weight of Sample	Range of Sample	Flour Supplier
1.1	11.3	0.8	Acme All-Rise
1.2	11.2	0.8	Acme All-Rise
1.3	10.9	1.1	Acme All-Rise
1.4	12.1	0.8	Acme All-Rise
2.1	11.0	0.7	Acme All-Rise
2.2	10.9	1.5	Acme All-Rise
2.3	11.0	0.6	Baker's Best
2.4	10.8	0.5	Baker's Best
3.1	10.9	0.6	Baker's Best
3.2	10.8	0.5	Baker's Best
3.3	10.9	0.5	Baker's Best
3.4	11.2	0.7	Acme All-Rise
4.1	11.1	1.4	Acme All-Rise
4.2	11.2	0.9	Acme All-Rise
4.3	10.8	0.6	Baker's Best
4.4	10.8	0.4	Baker's Best
5.1	11.0	0.8	Acme All-Rise
5.2	11.7	1.7	Acme All-Rise
5.3	10.8	0.7	Acme All-Rise
5.4	11.2	0.8	Acme All-Rise
6.1	10.8	0.4	Baker's Best
6.2	10.8	0.4	Baker's Best
6.3	11.0	0.8	Acme All-Rise
6.4	11.2	1.1	Acme All-Rise
7.1	10.8	0.8	Acme All-Rise
7.2	11.2	0.7	Acme All-Rise
7.3	10.9	0.7	Acme All-Rise
7.4	11.6	1.5	Acme All-Rise

Use excel to construct SPC charts for the cookie company based on what data was collected over the last 7 shifts (28 observations). YOU HAVE ENOUGH DATA TO COMPUTE THE ACTUAL UPPER AND LOWER CONTROL LIMITS. DO NOT USE THE ESTIMATE TABLE (A3, D3, D4, etc….) IN THE BOOK TO COMPUTE ESTIMATES. Use the results, and whatever other tools, logic, or understanding of TQM that you have learned in class to assess the situation.

Make sure your spreadsheet can answer the following questions, highlight the answers….

1. What is the standard deviation (sigma) for the X bar chart? The R chart?
2. What would be the 3 sigma upper and lower control limits for all 28 observations?

On a separate sheet, type brief answers to the following questions:

3. Does it appear to matter what type of flour was used? How can you tell?
4. Would it help to chart the cookies made with Baker flour apart from those made with Acme? Explain.
5. What is the sigma now (once separated)?
6. What recommenda­tions would you make for further improving this process and thereby improving the quality of the output?

Turn in X-bar and R charts to support your case.

Answer rating: 100% (QA)

1 Standard deviation of X bar chart 031 Standard deviation of R chart 035 2 for X bar Chart 3 sigma ... View the full answer