Solution Administracion y Control De La Calidad

Solutions to Even-Numbered Problems

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SOLUTIONS
CHAPTER 8

TO EVEN-NUMBERED

PROBLEMS

2. The general conclusion that can be reached for Imagimatrix from inspecting the data is that costs for internal and external failure are larger than they should be (totaling 47% of quality costs). Improvements that have been made to date have probably involved increasing prevention andappraisal costs that now stand at more than 50% of the total quality costs. Since appraisal costs are a large percentage of costs, and internal failures are a larger percentage than external failures, it is likely that quality is being “inspected in,” and many defective items are being taken out and reworked after being caught by inspection. More money and time needs to be invested in prevention, whichwill reduce defects and costs in other areas in a fairly short time. 4. An Excel chart can be constructed to show details on Product B sales and cost of quality presented in the problem, along with information on the percentage of total quality cost attributable to each cost category (external, internal, appraisal, and prevention). This problem contains time-phased data, unlike problem 1. Thus it ispossible to calculate an index base and quarterly indices for the various cost categories. The data show that the external and internal failure indices, as well as the appraisal index, are declining, while the prevention index is increasing. The overall quality cost index as a percent of sales is also declining. This is an ideal situation in which managers of the B product line are continuing toput more emphasis on prevention and attempting to reduce costs in other categories. 6. The data can be rearranged as follows:
Type of Cost Inspection and retest Scrap Customer returns Repair Quality equipment design Supplier quality surveys Cost Category Appraisal Int. failure Ext. failure Int. failure Prevention Prevention $ Costs Internal failure External failure Appraisal Prevention 410,00090,000 340,000 33,000 873,000 $ Cost 340,000 330,000 90,000 80,000 25,000 8,000 % of COQ 47.0 10.3 38.9 3.8 % of COQ 38.9 37.8 10.3 9.2 2.9 0.9

Although scrap is part of the process, Smith Company needs to minimize the amount of scrap produced, just as if it were making a product. The total cost of quality is $873,000. Although the categories are not completely clear, the assumed categories arelisted in the revised table above. Internal failure (scrap and repair) total 47% of quality costs, and external failure in the form of customer returns adds another 10.3%. Only 3.8 % of total costs are being applied to prevention. Apparently, based on high internal failure and appraisal costs, this organization is attempting to screen out bad product and scrap or repair it.

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Solutions toEven-Numbered Problems

Also, on this batch, they didn’t accomplish their goal of 60% of book value goal because (1,700,000 – 873,000)/1,700,000 = 48.65 %. 8. Miami Valley Aircraft Service Company’s data show rapidly decreasing total quality costs (except for a slight rise in the 4th quarter), possibly due to a concerted quality effort. The decrease in both internal and external quality costs,as a percentage of total quality and labor costs, while the prevention costs percentage is rising, is good. The only recommendation would be to increase prevention costs even more rapidly, while holding the line on appraisal costs However, the caution is that doing so may increase total quality costs in the short run, as may have happened in the 2nd quarter.
Percentages Quarterly Quality/LaborCosts 1 Qtr. External failure Internal failure Appraisal Prevention Total Quality/Labor Cost 5.13 17.95 4.62 2.05 29.74 2 Qtr. 4.74 17.11 6.32 2.63 30.79 3 Qtr. 4.52 14.29 5.48 2.62 26.90 4 Qtr. 3.82 11.58 4.53 4.21 24.13

10. Spreadsheet data and the Pareto chart for Repack Solutions, Inc. show that the company is spending too much on appraisal and internal failure cost and too little on...