In this tutorial, we will go through a performance analysis of the check-in process for QTP Airlines. The layout of the check-in area at one of the airports served by this fictional airline is illustrated above.
Note: This tutorial illustrates the approximate analysis of "non-Markovian queueing systems." All functions for analysing such systems have names that begin with "QTPGGS_". A separate tutorial (Tutorial 1) illustrates the analysis of simpler "Markovian queueing systems." We recommend completing Tutorial 1 before this one.
To go through this tutorial, you need to have Microsoft Excel open and QTP version 4 installed. This tutorial was written using Excel 2002.
The check-in area has ten check-in counters and five automated check-in terminals, as shown in the picture above. During the busiest part of the day, agents staff all ten check-in counters and an average of 480 passenger groups arrive per hour. (A passenger group consists of people that check in together. A group could consist of one person.) Seventy percent of the groups line up to be served by an agent and the other thirty percent use the automated check-in terminals. For simplicity, we assume that passenger groups decide how they are going to check in (at a counter or using a terminal) before they come to the airport.
In queueing theory terms, the check-in area can be viewed as two separate systems, one with human agents as servers and the other with computer terminals as servers. In both systems, the customers are arriving passenger groups.
A recent study measured the time required for check-in by several passenger groups. The results indicate that the average time required for check-in was 1.75 minutes for groups served by agents and 1 minute for groups using the automated check-in terminals. The standard deviation of the check-in time was 2 minutes for groups served by agents and 0.5 minutes for groups using the automated check-in terminals. Check-in times for groups using the automated check-in terminals were shorter and less variable because many of these groups consisted of frequent travellers, traveling alone with no luggage to check.