Question

    For the airport baggage handling system, generate use cases for dealing with baggage that is to be diverted to another flight.

Answer 1

Baggage handling is the process of transporting passenger luggage from a check-in counter at a departure airport, onto a plane cargo hold and then to a collection point at an arrival airport. A baggage handling system (BHS) is made up of a number of different processes and checks.

Baggage handling systems are among the most complex systems because they involve a wide variety of sensors, actuators, mechanical devices, and computers. The systems use over 3 million lines of software program code. Advanced technology used in these systems include destination-coded vehicles (DCV), automatic bar code scanners, use of radio frequency identification (RFID) tags, and high-tech conveyors equipped with sorting machines. Because DCVs move at high speed and do not come to a full stop to receive baggage, the conveyors must be extremely precise, depositing bags where they are needed at just the right time for maximum efficiency

The primary types of transactions handled by baggage handling systems are moving bags from check-in areas to departure gates, moving them from gate to gate and then finally, moving them from arrival gates to baggage claim areas. That's a lot of input data, processing and output.There is an off-ramp at every gate in the United Airlines terminal. The bags make their way down a short conveyor to a sorting station on the ground at the gate.

At the sorting station, baggage handlers load the bags onto carts or into special containers that go right into the airplane. When loading the plane, bags that will be making a transfer after the flight are loaded into separate areas than bags that will be heading to baggage claim. A monitor at the sorting station tells the handlers which bags are going where (remember, the baggage-handling system always knows exactly where each bag is going). Bags coming off a plane that are staying in Denver are loaded into carts and pulled by tug to the baggage-claim area. Since the bags are already sorted when they come off the plane, it is easy to keep the transferring bags separate from the terminating bags.

It is useful to differentiate between the different types of baggage. They are:

* ‘Local baggage’ that is checked in at the airport
* ‘Transfer baggage’ arrives at an airport on one flight and leaves on another. This is divided into two sub-categories; ‘short connecting baggage’, defined by less than 45 minutes of transfer time, and ‘early baggage’ which incorporates more than three hours of transfer time.
* ‘Bulky baggage’, OOG (Out Of Gauge), that exceeds normal dimensions that are not suitable to be sorted with normal conveyor belts.
* ‘Special’ items that arrive at the plane with the passenger such as wheelchairs.

Transfer baggage could be handled in the following ways, depending on the airport infrastructure:

· On to the same sorting system as local baggage

· On a separate sorting system

· Manually on a simple carousel

· Directly, from arriving to the departing plane, also known as ‘tail-to-tail’ baggage. This procedure is normally used for ‘short connecting baggage’ only.

A bag is entered into the baggage handling system when an airline agent, or self check system, assign the luggage a tag with a unique ten digit barcode. Airlines are also incorporating RFID chips into the tags to track bags in real time and to reduce the number of mishandled bags. The BHS will then scan and sort the bags by airline. Then a series of diverters along the conveyor belt will direct the bags into the baggage handling area.

Although the primary function of a BHS is the transportation of bags, a typical BHS will serve other functions involved in making sure that a bag gets to the correct location in the airport.

In addition to sortation, a BHS may also perform the following functions:

· Detection of bag jams

· Volume regulation (to ensure that input points are controlled to avoid overloading system)

· Load balancing (to evenly distribute bag volume between conveyor sub-systems)

· Bag counting

· Bag tracking

· Automatic Tag Reader (ATR) (Reads the tags on the luggage provided by the airlines)