Risk assessment is the primary justification for the extra effort needed to generate a PERT network. For example, given µ = 38 months and σ2 = 5 for the construction of a coal-fired power plant:
1. When will the power plant come on-line with a 90% probability?
2. The utility company would like to apply for a permit to operate the facility three years after award of the contract. What is the probability the plant will be on-line on time?