The city of Bloomington is about to build a new water treatment plant. After the plant is designed (D), we can select the site (S), the building contractor (C), and the operating personnel (P). After...

The city of Bloomington is about to build a new water treatment plant. After the plant is designed (D), we can select the site (S), the building contractor (C), and the operating personnel (P). After the site is selected, we can erect the building (B). We can order the water treatment machine (W) and prepare the operations manual (M) only after the contractor is selected.

We can begin training (T) the operators when both the operations manual and operating personnel selection are completed. When the treatment plant and the building are finished, we can install the treatment machine (I). After the treatment machine is installed and operators are trained, we can obtain an operating license (L). Assume that the time (in months) needed to complete each activity is normally distributed, with the means and standard deviations given in the file P15_31.xlsx. Use simulation to estimate the probability that the project will be completed in (a) under 50 days and (b) more than 55 days. Also estimate the probabilities that B, I, and T are critical activities.