he presence of luggage was defined as any object that the customer was required to have x-rayed. This included
luggage, boxes, and radios.
5. Travel Time
This is defined as the time required after the end of the ticket-checking time and before arrival at either the x-ray
machine, the metal detector, or the queue of either.
6. X-Ray Service Time
X-ray service time begins with the customer first placing objects on the end of the x-ray machine. The service time
includes the time required by the x-ray operator to inspect the objects and ends when the individual removes the
luggage. Data for this specific service time were recorded so that they were not dependent on the time the passenger
was being processed through the metal detector. Thus, these data reflect the system time that can be attributed to the
presence of baggage.
7. Metal Detector Service Time
The collection of metal detector service times depended on whether the customer possessed luggage. In the case of
no luggage, metal detector service time began with passenger passing the front of the x-ray machine. In the case of
the presence of luggage, the time began when the passenger released the luggage onto the front of the x-ray machine
and began forward movement toward the metal detector. Service time includes the period during which the customer
has exclusive control over the metal detector and operator. Time includes the customer passing through the metal
detector. Time ends when either the customer is not stopped by the operator and physically passes the operator or
fails the inspection and passes backwards through the metal detector. Observations of customers who failed the
metal detector indicated that other customers passed through the metal detector while the failed customer searched
for possible causes of failure.
8. Customer Metal Detection Failure
This occurred when the customer failed to remove suspect metal objects from his/her person. These data were
collected on the basis of the number of customers who failed out of the total number of customers observed.
Data Fitting
This section consists of fitting the observed data to theoretical probability distributions. Distribution fitting was
conducted with the chi-square and Kolmogorov–Smirnov goodness of fit tests.
1. Interarrival Times of Customer Batches to the Checkpoint
This data were fitted to a lognormal distribution with a mean of 3.14 and a standard deviation of 3.07.
2. Customer Arrival Batch Size
These data were fit to a geometric distribution. In this case, the empirical distribution was modified by subtracting
one from each observation. Thus, the batch size minus one was fit to a geometric distribution with p = 0.552695.
3. Ticket-Checking Service Time
These data were fit to a gamma distribution with an value = 1.91 and a value of 0.99.
4. Travel Time
Travel time to the x-ray/metal detector group I was fit for coming from a uniform distribution [0.8, 2.2] thousandths
of hours. Travel time to the x-ray/metal detector group 2 was fit for coming from a uniform distribution [1.1, 3.2]
thousandths of hours.
5. The Presence of Luggage
These data consisted of the observation that, of the customers observed, 10% did not possess objects that required
being x-rayed. This is a Bernoulli trial with only one of two outcomes: the customer has objects or the customer
does not.
6. X-Ray Service Time
These data were missing, so you will need to assume this distribution. Before you make any assumption, you should
do some research to find the information to support your assumption. You may do some research on internet like
Google. Please state your assumption and the reason why this assumption is suitable for this data.
7. Metal Detector Service Time
These data were missing, so you will need to assume this distribution. Before you make any assumption, you should
do some research to find the information to support your assumption. You may do some research on internet like
Google. Please state your assumption and the reason why this assumption is suitable for this data.
8. Customer Metal Inspection Failure
These data consisted of the observation that 3% of the customers observed failed the inspection. This is
a Bernoulli trial with one of two possible outcomes: the customer fails the inspection, or the customer
does not.
6. X-Ray Service Time
These data were missing, so you will need to assume this distribution. Before you make any assumption, you should
do some research to find the information to support your assumption. You may do some research on internet like
Google. Please state your assumption and the reason why this assumption is suitable for this data.
7. Metal Detector Service Time
These data were missing, so you will need to assume this distribution. Before you make any assumption, you should
do some research to find the information to support your assumption. You may do some research on internet like
Google. Please state your assumption and the reason why this assumption is suitable for this data.
8. Customer Metal Inspection Failure
These data consisted of the observation that 3% of the customers observed failed the inspection. This is
a Bernoulli trial with one of two possible outcomes: the customer fails the inspection, or the customer
does not.