Consider the HBS OM Simulation Intensive Care Unit (ICU) environment in Scenario 1 with 4 beds and the following parameter values: Mean Inter-arrival Time = 5 hours, Mean Length of Stay = 16 hours, Std.Dev. of Inter-arrival Time = 4 hours, Std.Dev. of Length of Stay = 8 hours.

You are told that the simulation estimate of the average waiting time in the queue for this data set is 281 minutes or 4 hours 41 minutes. How does this simulation estimate compare with your answer in 1 above? Provide three sets of reasons for any differences between the answer from the Tq formula and the simulation estimate. (A set of reasons is a general category, e.g., the simulation computer code has a bug, that covers several reasons like the software was not correctly written, it was not compiled / run correctly, the model is not valid, etc., all of which relate to coding errors.) Which average waiting time is more correct, the formula or the simulation, and why?