This paper aims to support Natalie York, the operations manager at Harnswell Sewing Machine Company (HSMC), in her intent to improve product quality in the company. In addition to analyzing production process data of half-inch cam rollers and explaining the results, this paper also gives advice on which actions Natalie should take and how she should approach the CEO and founder of her company. Phase 1 Based on the given description of the HSMC, points 1, 2 and 7 of Deming’s 14 points for management seem to be most lacking in the company. . Create constancy of purpose for improvement of product and service. 2. Adopt new philosophy. 7. Adopt and institute leadership. There is a huge need of organizational transformation in the HSMC and its CEO and founder, Mr. Harmswell, is currently not aware of this need. According to his own words (“if it ain’t broke, don’t fix it”), he is not striving for constant improvement and does not act proactively. Rather than supporting his employees in thinking about how to improve their working environments, Mr. Harmswell relies on his past experiences.
He even actively discourages his employees from “making waves” and uses fear as an instrument to paralyze the people in his organization (“What am I going to do with you if you keep coming up with these ridiculous ideas”). This indicates that he is rather supervising than leading his employees. Natalie York should think very carefully about her next steps and focus on the specific problem she discovered and not the whole production process when she approaches Mr. Harmswell next time. Natalie will only be able to implement changes when she comes to her boss backed with profound data analysis.
Besides the data-based evidence of problems in certain parts of the production process, Natalie should show Mr. Harmswell the positive impact changes will have on the profit of HSMC. Keeping her language simple and her explanations easily understandable is another key for the success of her next steps. After Natalie successfully implemented a couple of smaller changes in parts of the production, Mr. Harmswell might rethink his attitude towards constant improvement and give her more freedom to have a positive impact on the organization. Phase 2:
Using the given data about the diameter of cam rollers, we use Minitab to create a “Xbar-R Chart“, as shown in Chart 1 of the appendix. From this chart, we can draw the conclusion that Day 17 is below the LCL, out of control limit. Therefore one can say the whole process is out of control. Natalie notices that the average diameter of batch 17 is extremely low compared to the average diameters of the other batches. Our recommendation to Natalie is that she should check what happened on Day 17 to find the reasons for these out-of-control-results.
As the next step, Natalie should take the required actions for solving the discovered problem. Phase 3: After Natalie’s further investigation, it turns out that the reason for the particularly bad results of work on Day 17 is the low temperature in the morning on which the batch was produced. By installing a thermostat in the manufacturing hall they solve this problem. Now, what Natalie should do next is to take this special batch out of the data and draw another Xbar-R chart. After excluding this special case from the data, Natalie can evaluate the rest of the data independently from this “special event”.
The new Xbar-R chart shows this one special batch is not the reason why cam rollers always fall short. From the new chart, Natalie might identify what might be the other causes that result in the shortage. For further information, please refer to Chart 2 in the appendix. Natalie and Jim install the thermostat and set the heating control so that heats turns on half an hour before the machine starts to work in the morning. These actions have a positive impact on improving the product quality as the scrap defects were caused by cold temperatures, affecting the normal running of the equipment.
After setting the heating control, the machine will warm up to acceptable temperatures in the cold weather. By doing this, any scraps caused by the abnormal status of the equipment in cold weather will be avoided. Phase 4: Chart 3, the histogram of diameters, and Chart 4, the stem-and-leaf display, show that the range is from 0. 5072 to 0. 5077, which means all cam rollers meet the lower specification of 0. 5072 but some exceed the upper specification 0. 5075. The mean of the 150 sample diameters’ is 0. 5075. The mean diameter equals the upper limit of the diameter. There are 71 cam rollers having a diameter of 0. 075, accounting for 47. 3% of all samples; 49 cam rollers have diameter of 0. 5076, accounting for 32. 7% of all samples; 7 cam rollers have diameter of 0. 5077, accounting for 4. 7% of all samples. Chart 5, the pie chart of distribution of diameters, shows that there are 56 cam rollers which have a larger diameter than 0. 5075, while there are only 23 cam rollers with diameters below 0. 0575. 56 of the 150 rollers, comprising 37. 3%, are above the specification value. Therefore 37. 3% of them will be reclassified into a different and less costly category, which decreases total revenues and profits of HSMC.
If this percentage is applied for the total years’ production, out of 7000 cam rollers 2614 will not be available for sale at normal price. Phase 5: Dave Martin, the machinist at HSMC, is already aware of the reasons why he has been producing many oversized cam rollers. With operating room of 0. 0003 inch, he has been aiming for the upper level of diameter because he did not want to produce undersized cam rollers which have to be scrapped. Dave Martin simply did not want to have trouble with Mr. Hanswell and other senior managers of the company.
Natalie first needs to persuade Dave to adjust his aim to the exact center value and try to manufacture accordingly. Of course, Natalie needs to give Dave an assurance that he would not be held liable for the results. Because Natalie already has all the data she needs to conform to her forecast, we think it is time to go to Mr. Harmswell. She should show him that there exist some real problems and tell him the importance and positive benefits of adopting changes at HSMC. But she should be very careful not to overload her boss with too many graphs and numbers.