Answer:
a. To determine the maximum increase in the payoff under strong demand that would still keep decision alternative d2 (medium complex) as the optimal solution, we need to find the threshold value.
From the sensitivity analysis, the threshold value for the payoff under strong demand is $17.82 million for the large complex. Therefore, the maximum increase in the payoff under strong demand for the medium complex while still keeping the large complex as the optimal solution would be $17.82 million.
b. Similarly, to find the maximum increase in the payoff under strong demand that would still keep decision alternative d3 (small complex) as the optimal solution, we need to determine the threshold value.
According to the given information, the threshold value for the payoff under strong demand is not provided for the small complex. Hence, without the specific threshold value for the small complex, we cannot determine the exact maximum increase in the payoff under strong demand while keeping the large complex as the best decision.
Please note that the value of the threshold for the small complex under strong demand is missing from the provided information.