The first addition to the elevator model is the central queue. In this case, no longer will each elevator have its own queue. Only one (central) queue will be available for the employees. The employee that's at the front of the queue, will choose the first available elevator and when there is more than one elevator available, he/she will choose the nearest. Examining the statistics will learn that the average queue length will increase, but the average queue time will decrease.
Secondly, it is possible to add a staircase to the elevator system. An arriving employee can now decide to take the stairs, instead of an elevator. Only the employees with destinationfloors lower than five will have the opportunity to do this. Their choice (stairs or elevator) will depend on the availability of the elevators, the length of the queue and their floornumber (employees with floornumber 1 or 2 will take the stairs sooner than the employees with destinationfloors 3 or 4).
Furthermore, if there are two or more elevators there is a possibility to send the elevators to different floordestinations. Two options are available: elevators that only visit the odd or even floors or elevators that only visit specific floors. In both cases the employee can only choose between the queues of the elevators with destinationfloors, that include the floornumber of the employee. It is not possible to select a central queue together with one of these two options, because this situation would be quite unrealistic (the employee chooses at the front of the queue). In certain situations the average service time of an employee will now decrease.
Finally, the time between the arrivals of the employees can be chosen: high, normal or low arrivaltimes. In general, a higher arrivaltime will increase the average queue length and queue time, but also more employees will decide to take the stairs.
In this lesson you can store your simulation statistics. Use the 'Save' button to save the current statistics table and with the 'Delete' button you can delete the visible stored statistic. With this function you can compare your simulations.