We have done some statistical analysis on our hotel, and come up with the following information.
Our hotel has 850 Standard rooms, and 150 Family rooms. There are an average total of 660 total requests for a reservation a day. On average, 80% of the calls per hour are for a Standard room; 20% are for a Family room. This translates to an average of 528 calls for a Standard room per day and 132 for a Family room. The average stay for a person reserving a Standard room is 2 days; the average stay for a person requesting a Family room is 3 days. The average capacity is 90 percent in both situations. Here is a summary of this information:
Standard rooms
Family rooms
No Requests:
528
132
No Rooms:
850
150
Average Stay:
2
3
Average Capacity:
90%
90%
The formula for predicting the probability of a room being available is:
Probability Room Available% = [(number of rooms)/(average stay)] x Avg occupancy]/ (Number of Calls)
Therefore, the probability of a room being available for a Standard room and for a Family room is:
Standard = [(850/2) x .9]/528 = 72.4 percent
Family = [(150/3) x .9]/132 = 34.1 percent
1 On the Sequence Flow line named Standard Yes, drawn from the XOR gate “Standard Room Available” to the process OK, set the probability to 72 percent.
2 On the Sequence Flow line named Standard No, drawn from the XOR gate “Standard Room Available” to the process No, set the probability to 28 percent.
3 On the Sequence Flow line named Family Yes, drawn from the XOR gate “Family Room Available” to the process OK, set the probability to 34 percent.
4 On the Sequence Flow line named Family No, drawn from the XOR gate “Family Room Available” to the process No, set the probability to 66 percent.
Specify the End event on the diagram
Finally, since this is a child diagram, we must specify on the End event that the objects (in this case Reservation objects) coming from this child diagram get passed as throughput.
1 Open the definition of the End event End Availability Check.
2 Within the definition, specify this event as an End event on the Sim Definition tab, and then click Apply. A Sim Result tab will appear.
3 On the Sim Result tab, make sure the Pass Objects (Terminate) property is toggled ‘on’. This will make sure that the objects (in this case Reservation objects) coming from this child diagram get passed as throughput.
4 In the Goal or Reject property of Service Levels group of controls, toggle ‘on’ Neither. If you leave this as a Goal, the Reservations leaving will be counted as throughput in your output, in addition to the Reservations output from the parent diagram. We set it to neither because we do not want it counted twice.
