(AC) unit for the first two years of operation (that is, the warranty period). AC failures are usually due to stresses such as dirty coils, low refrigerant, electrical problems. On average, an AC unit operates 1500 hour/year, however, the actual working hours varies depending on usage circumstances. In order to calculate warranty cost, JEI wants to estimate the percentage of returns that can be expected during the first two years of operation. First, JEI tested their AC unit at different loads and data of table 1 was generated. Next, JEI obtained the customer usage information by conducting a survey on a representative sample of customers and recording the "hours/day" loads that they use. This is given in table 2 below. Tablel: Percent of AC units failing during warranty. Operating "hours/day" Percent failed during the first two years I and less 0.1% 1-3 0.5% 3-6 0.8% 6-9 1.3% 9-12 2% 12-15 4% 15-18 6% 18-21 10% 21-24 15% Table 2: Operating loads vs. percentages of the users applying those loads Operating hours/dayk Percent of users I and less 5% 30% 4-8 30% 8-12 10% Above 12 59% Tasks 1. Conduct appropriate analysis and find what percent of AC units will fail during the Warranty period. 2. If a failure will cost 30000 D in total poor cost of quality/reliability, and reducing 0.1% of failures will cost 200000 JD, do you recommend implementing such development? (State all assumptions made and comment on whether you consider them reasonable) (AC) unit for the first two years of operation (that is, the warranty period). AC failures are usually due to stresses such as dirty coils, low refrigerant, electrical problems. On average, an AC unit operates 1500 hour/year, however, the actual working hours varies depending on usage circumstances. In order to calculate warranty cost, JEI wants to estimate the percentage of returns that can be expected during the first two years of operation. First, JEI tested their AC unit at different loads and data of table 1 was generated. Next, JEI obtained the customer usage information by conducting a survey on a representative sample of customers and recording the "hours/day" loads that they use. This is given in table 2 below. Tablel: Percent of AC units failing during warranty. Operating "hours/day" Percent failed during the first two years I and less 0.1% 1-3 0.5% 3-6 0.8% 6-9 1.3% 9-12 2% 12-15 4% 15-18 6% 18-21 10% 21-24 15% Table 2: Operating loads vs. percentages of the users applying those loads Operating hours/dayk Percent of users I and less 5% 30% 4-8 30% 8-12 10% Above 12 59% Tasks 1. Conduct appropriate analysis and find what percent of AC units will fail during the Warranty period. 2. If a failure will cost 30000 D in total poor cost of quality/reliability, and reducing 0.1% of failures will cost 200000 JD, do you recommend implementing such development? (State all assumptions made and comment on whether you consider them reasonable)
