Aquaguard manufactures three models of water purifiers in three separate plants at Taiwan. These plants serve the demand in Europe. All three models sell at a unit price of $100 and the holding cost is 5% of the selling price per month. The monthly demand for these models is normally distributed with the following parameters:
Model 1: Mean 1000, SD 300
Model 2: Mean 1000, SD 300
Model 3: Mean 1000, SD 300
The demand for Model 1 and Model 2 has a correlation coefficient of (-) 0.35, while that for Model 3 is independent of the other two models. The company wishes to make two of the models in one plant by using flexible technology.
Required:
a) Which two models should Aquaguard choose in order to minimize production variability in the new plant? (as measured by the coefficient of variation).