Variability and Waiting Times Chapter 8 (Max 25 Points): 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.

(10 points) Calculate the theoretical average waiting time in queue using the formula for Tq from (

*10 points) 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?

(5 points) Answer ANY ONE of the following: What options would you consider for improving the waiting time performance of this particular hospital ICU? How might each specific improvement be implemented or lead to improvement?

List three key lessons specific to this HBS OM Simulation and discuss how each of these lessons are different from those in other parts of the Variability and Waiting Lines course materials in Modules 3-4.