A Data Flow diagram is a graphical technique used to abstract the operation of a system in a given environment. They explicitly show how information flows to and from the system and how this information is transformed along the way. The following Data Flow diagrams have been created to provide such an overview for IFESS.
Data Flow diagrams are drawn in nested layers. They start with the most general representation of the system and work down into specific sections. In the following diagrams, there are labeled bubbles representing different components of the system. For each bubble, a more detailed description will be given in the individual diagram corresponding to the component name. For clarity, a legend of the symbols used in Data Flow diagrams is given below. In addition, the following generic rules are the main guidelines:
- Arrowheads indicate which way the data is flowing.This high-level view shows how IFESS will interact with its environment; such a schematic is also referred to as a context diagram. The entire IFESS system is represented by a central bubble, which has directed arcs specifying its general input and output. In this diagram it is also easy to see the many entities that supply input to IFESS and its many facets for output.
The level one diagram is an expansion of the singular IFESS bubble in the previous schematic. It shows all of the major components of the system and indicates which of these components the input and output arcs from the level zero diagram belong to. Also, the input and output arcs are more specific, and now the label indicates what specific data is flowing. The purpose of this level is to clarify the breakdown of the entire software system into its major components.
This simple diagram describes how IFESS provides access to the Internet. Passengers input information into the IFESS Internet browsing tool, prompting IFESS to retrieve the content from the Internet and output it to the Display system.
Illustrated here is the system functionality that deals with food orders and meal reservations. Passengers and pilots are able to reserve a meal from a list of available choices, as well as order individual food items. Also shown is how they can change their selection meals anytime before the cutoff. Flight attendants can both view pending orders and mark them as delivered. All information storage is done through the food data store, which gets revised regularly by the update system.
Another simple diagram showing how IFESS provides the passengers with access to basic games such as hearts and FreeCell. Passengers select the game that they want to play and IFESS displays the game on the passenger’s terminal. It then takes inputs from the user and outputs the visual and audio game information to the display system and headphones respectively.
This diagram describes the comprehensive IFESS billing and account tracking system. This system accepts billing information from both the food and movie systems, and updates the passenger-specific billing information in the billing/account information data store. The diagram shows how passengers can view their individual account information and how flight attendants can access passenger information, add a payment to an account, and print a permanent account record. The arc leading to the billing/account information data store from the update system depicts this update of information.
This diagram shows the data flow to and from the movie system. The functionality includes selecting a movie, watching it, and controlling the playback. When a movie is selected, the system sends the movie and passenger information to the billing system in order to update the account balance. It also internally determines if the passenger is required to pay for watching the selected movie. From there, the movie file is found in the data store and played on the passenger’s terminal, the audio information going to the headphones while the video stream goes to the display. During play, the system also handles passenger control of the movie’s progress through standard stop, pause, re-wind, and fast-forward commands.
Shown here is how various IFESS components access the display system to output information to the user. There are nine components accessing the display system: information update, music, food, in-flight info, billing/accounts, movies, games, Internet, and help. There is also functionality to display core information, which involves the display of core items such as the IFESS user interface.
This diagram describes the data flow to and from the music system. If covers all related functionality, including listening to pre-recorded music tracks and listening to the radio. Radio stations interact with IFESS by sending the radio station stream via the web. Passengers send requests for stations or music type, which sends the appropriate audio to the headphones. For pre-recorded music tracks, track progress is also sent to the video display.
This diagram describes how passengers interact with the flight information system. A passenger request on the status of the flight prompts IFESS to retrieve the information from the data store and generate a status report. This report is formatted into readable display information and sent to the terminal. The data store is constantly updated by the in-flight information, so passengers can always see an up-to-date outlook of the flight status.
This is a simple diagram that depicts how the information in all of the IFESS system’s data stores is updated. For clarity, all of the IFESS data stores have been represented as one universal data store. This is merely an abstract representation, and is not meant to imply any implementation choices. It is to this universal data store that the administrator inputs updated information. The updated information is then sent to the appropriate local data store.
This straightforward diagram shows how the various IFESS users can access help files for all IFESS operations. Passengers, Flight Attendants, Pilots and Administrators can all access this system. When they input a help section to view, the system retrieves the help files from the data store, and the information is sent to the display.
| Term |
Movie Item |
|
Location(s) of Use: |
Movie, Billing/Accounts |
|
Description: |
IFESS representation of a movie. |
|
Term: |
Administrator Inputs |
|
Location(s) of Use: |
Level 0 |
|
Description: |
All the possible inputs the Administrator may use. |
|
Term: |
Altitude |
|
Location(s) of Use: |
Level 0, In-flight Info |
|
Description: |
Current Altitude of the plane |
|
Term: |
Audio |
|
Location(s) of Use: |
Level 0 |
|
Description: |
All sound that is output to the headphones. |
|
Term: |
Audio Signal |
|
Location(s) of Use: |
Level 0, Movies, Music |
|
Description: |
Movies and Music both generate Audio output in the form of an Audio Signal |
|
Term: |
Billing display data |
|
Location(s) of Use: |
Display |
|
Description: |
The information from Billing that is to be displayed. |
|
Term: |
Billing info |
|
Location(s) of Use: |
Level 0 |
|
Description: |
All the information that is pertinent to Billing. Information such as Seat Number and Passenger ID are a couple of examples. |
|
Term: |
Billing/Account info |
|
Location(s) of Use: |
Level 0, Billing/Accounts, Display |
|
Description: |
The accumulated information from Billing/Accounts that is to be displayed. |
|
Term: |
Browsing instructions |
|
Location(s) of Use: |
Level 0, Internet |
|
Description: |
Instructions from the user to control the browsing of the Internet. |
|
Term: |
Category |
|
Location(s) of Use: |
Level 0, Help |
|
Description: |
A subsection of the Help File. |
|
Term: |
Confirmation |
|
Location(s) of Use: |
Billing/Accounts |
|
Description: |
Action to ensure correct data input. |
|
Term: |
Core Display data |
|
Location(s) of Use: |
Display |
|
Description: |
Display data corresponding to the representation of information in the data store. |
|
Term: |
Cost |
|
Location(s) of Use: |
Level 0, Food, Billing/Accounts, Movie |
|
Description: |
The price of an item. |
|
Term: |
Database output |
|
Location(s) of Use: |
Level 0 |
|
Description: |
Information transferred from the plane to the airport. |
|
Term: |
Deliver Orders |
|
Location(s) of Use: |
Food |
|
Description: |
Message indicating that a food order has been delivered. |
|
Term: |
Description |
|
Location(s) of Use: |
Food, Billing/Accounts |
|
Description: |
General description of an item. |
|
Term: |
Detailed account info |
|
Location(s) of Use: |
Billing/Accounts |
|
Description: |
Account information to be processed. |
|
Term: |
Detailed account record |
|
Location(s) of Use: |
Level 0, Billing/Accounts |
|
Description: |
Account information to be printed. |
|
Term: |
Displayable flight info |
|
Location(s) of Use: |
Level 0, Display, In-Flight Info |
|
Description: |
Data required for displaying the flight status. |
|
Term: |
ETA |
|
Location(s) of Use: |
Level 0, In-Flight Info |
|
Description: |
Estimated Time of Arrival of the flight. |
|
Term: |
Fast Forward |
|
Location(s) of Use: |
Movie, Music |
|
Description: |
Fast Forward a movie or music option. |
|
Term: |
Files |
|
Location(s) of Use: |
Information Update |
|
Description: |
The physical files needed to be updated during administrative maintenance. |
|
Term: |
Flight attendant inputs |
|
Location(s) of Use: |
Level 0 |
|
Description: |
All possible inputs the Flight Attendant will need to enter. |
|
Term: |
Flight Data |
|
Location(s) of Use: |
In-Flight Info |
|
Description: |
All flight data pertinent to the Flight status, such as Altitude and ETA. |
|
Term: |
Food Adjustments |
|
Location(s) of Use: |
Level 0 |
|
Description: |
Adjustments made to the way food is represented on the system. |
|
Term: |
Food display data |
|
Location(s) of Use: |
Display |
|
Description: |
All data required for displaying food information. |
|
Term: |
Food info |
|
Location(s) of Use: |
Level 0, Food, Display |
|
Description: |
All data associated with Food. |
|
Term: |
Food item |
|
Location(s) of Use: |
Level 0, Food, Billing/Accounts |
|
Description: |
Individual item of food, eg. A turkey sandwich. |
|
Term: |
Food Order |
|
Location(s) of Use: |
Level 0, Food |
|
Description: |
Contains a collection of Food Items. |
|
Term: |
Game display data |
|
Location(s) of Use: |
Display |
|
Description: |
Data required to display games. |
|
Term: |
Game Info |
|
Location(s) of Use: |
Display, Information Update |
|
Description: |
All pertinent information relating to Games, eg. The name of the game. |
|
Term: |
Game List |
|
Location(s) of Use: |
Information Update |
|
Description: |
List of games available. |
|
Term: |
Game play instructions |
|
Location(s) of Use: |
Level 0 |
|
Description: |
Input from user to control the game play. |
|
Term: |
Help Display data |
|
Location(s) of Use: |
Level 0, Help, Display |
|
Description: |
Data required to display Help. |
|
Term: |
Help Files |
|
Location(s) of Use: |
Help |
|
Description: |
Physical files containing the text for help. |
|
Term: |
Help request |
|
Location(s) of Use: |
Level 0 |
|
Description: |
Request for help on a topic. |
|
Term: |
Help Section Request |
|
Location(s) of Use: |
Help |
|
Description: |
Section of help desired. |
|
Term: |
IFESS core data |
|
Location(s) of Use: |
Display |
|
Description: |
Main data at the heart of the IFESS system. |
|
Term: |
In-flight display data |
|
Location(s) of Use: |
Display |
|
Description: |
Data required to display the in-flight status of the plane. |
|
Term: |
Internet Content |
|
Location(s) of Use: |
Display, Internet |
|
Description: |
Visual data retrieved from the Internet. |
|
Term: |
Meal |
|
Location(s) of Use: |
Food |
|
Description: |
Prearranged grouping of Food Items. |
|
Term: |
Meal Adjustments |
|
Location(s) of Use: |
Information Update |
|
Description: |
Adding, removing, adjusting meal listings. |
|
Term: |
Meal ID |
|
Location(s) of Use: |
Food |
|
Description: |
Identification of a type of meal. |
|
Term: |
Movie |
|
Location(s) of Use: |
Movies |
|
Description: |
Data representation of a movie. |
|
Term: |
Movie audio |
|
Location(s) of Use: |
Level 0 |
|
Description: |
Audio emitted from a movie. |
|
Term: |
Movie Info |
|
Location(s) of Use: |
Display |
|
Description: |
Movie description information to be displayed. |
|
Term: |
Movie Item |
|
Location(s) of Use: |
Movie, Billing/Accounts |
|
Description: |
IFESS representation of a movie. |
|
Term: |
Movie Name |
|
Location(s) of Use: |
Movie |
|
Description: |
Name of a movie. |
|
Term: |
Movie Request |
|
Location(s) of Use: |
Level 0, Movie |
|
Description: |
User request for a movie to be played. |
|
Term: |
Movie Video Stream |
|
Location(s) of Use: |
Level 0, Movie, Display |
|
Description: |
Video display generated from a movie. |
|
Term: |
Music Display data |
|
Location(s) of Use: |
Display |
|
Description: |
Information describing Music to be displayed. |
|
Term: |
Music Info |
|
Location(s) of Use: |
Information Update |
|
Description: |
Information for updating the status of the music list. |
|
Term: |
Music List |
|
Location(s) of Use: |
Information Update |
|
Description: |
List of all available music. |
|
Term: |
Music progress |
|
Location(s) of Use: |
Level 0, Music, Display |
|
Description: |
Progress of music as it is playing. |
|
Term: |
Music/Radio request |
|
Location(s) of Use: |
Level 0 |
|
Description: |
User request to listen to music or to the radio. |
|
Term: |
Order |
|
Location(s) of Use: |
Food |
|
Description: |
General food/snack item order information. |
|
Term: |
Passenger ID |
|
Location(s) of Use: |
Level 0, Food, Movies, Billing/Accounts |
|
Description: |
Passenger’s unique identification number within the system. |
|
Term: |
Passenger Inputs |
|
Location(s) of Use: |
Level 0 |
|
Description: |
General data associated with passenger interaction with IFESS. |
|
Term: |
Pause |
|
Location(s) of Use: |
Movies, Music |
|
Description: |
User request to pause movie or music playback. |
|
Term: |
Payment |
|
Location(s) of Use: |
Billing/Accounts |
|
Description: |
Data associated with a customer payment. |
|
Term: |
Play |
|
Location(s) of Use: |
Movies, Music |
|
Description: |
User request to play a loaded movie or music option. |
|
Term: |
Playback Control Request |
|
Location(s) of Use: |
Movies, Music |
|
Description: |
User request to manipulate the playback of a song or movie, throughout the use of: play, pause, rewind, stop, and fast forward |
|
Term: |
Position |
|
Location(s) of Use: |
Level 0, In-Flight Info |
|
Description: |
Flight position as given by the onboard flight information system. |
|
Term: |
Price |
|
Location(s) of Use: |
Food, Billing/Accounts |
|
Description: |
The price of a food system item. |
|
Term: |
Quantity Change |
|
Location(s) of Use: |
Food |
|
Description: |
Integer value of change that is required. |
|
Term: |
Radio Stream |
|
Location(s) of Use: |
Music |
|
Description: |
Data stream for radio stations. |
|
Term: |
Relevant Flight Info |
|
Location(s) of Use: |
In-Flight Info |
|
Description: |
Human readable generated flight info from raw flight info data. |
|
Term: |
Request for Passenger Account Info |
|
Location(s) of Use: |
Level 0, Billing/Accounts |
|
Description: |
User request to get passenger account information. |
|
Term: |
Request Game |
|
Location(s) of Use: |
Level 0 |
|
Description: |
User request to play a game. |
|
Term: |
Request Meal |
|
Location(s) of Use: |
Food |
|
Description: |
User request to reserve a meal. |
|
Term: |
Request Orders |
|
Location(s) of Use: |
Food |
|
Description: |
User request for a list of pending food orders. |
|
Term: |
Request Price |
|
Location(s) of Use: |
Food |
|
Description: |
User request for the price of an item. |
|
Term: |
Request to Cancel Meal |
|
Location(s) of Use: |
Food |
|
Description: |
User request to cancel a meal order. |
|
Term: |
Rewind |
|
Location(s) of Use: |
Movies, Music |
|
Description: |
User request to rewind movie or music selection. |
|
Term: |
Seat Number |
|
Location(s) of Use: |
Food, Billing/Accounts |
|
Description: |
The unique seat number associated with a transaction. |
|
Term: |
Song |
|
Location(s) of Use: |
Music |
|
Description: |
The playable song data. |
|
Term: |
Song Title |
|
Location(s) of Use: |
Music |
|
Description: |
The title of a playable song. |
|
Term: |
Station Data |
|
Location(s) of Use: |
Level 0, Music |
|
Description: |
Information about a radio station. |
|
Term: |
Station Identifier |
|
Location(s) of Use: |
Music |
|
Description: |
Unique identifier for a radio station. |
|
Term: |
Status Request |
|
Location(s) of Use: |
Level 0, In-Flight Info |
|
Description: |
User request for flight status information. |
|
Term: |
Stop |
|
Location(s) of Use: |
Movies, Music |
|
Description: |
User request to stop a playing movie or audio stream. |
|
Term: |
Time |
|
Location(s) of Use: |
In-Flight Info |
|
Description: |
Time of day at origin and destination. |
|
Term: |
Update Amount |
|
Location(s) of Use: |
Billing/Accounts |
|
Description: |
Information concerning transaction. |
|
Term: |
Update Feedback |
|
Location(s) of Use: |
Information Update, Display System |
|
Description: |
Feedback from a data update procedure. |
|
Term: |
Update Info Display |
|
Location(s) of Use: |
Display System |
|
Description: |
Visible feedback from information update system. |
|
Term: |
Updated Account Info |
|
Location(s) of Use: |
Level 0, Billing/Accounts |
|
Description: |
The account data that has been changed. |
|
Term: |
Updated Food List |
|
Location(s) of Use: |
Information Update |
|
Description: |
The data associated with a new/changed food list. |
|
Term: |
Updated Game List |
|
Location(s) of Use: |
Information Update |
|
Description: |
The data associated with a new/changed game list. |
|
Term: |
Updated Movie List |
|
Location(s) of Use: |
Information Update |
|
Description: |
The data associated with a new/changed movie list. |
|
Term: |
Updated Music List |
|
Location(s) of Use: |
Information Update |
|
Description: |
The data associated with a new/changed music list. |
|
Term: |
Velocity |
|
Location(s) of Use: |
Level 0, In-Flight Info |
|
Description: |
Flight velocity information. |
|
Term: |
View Orders |
|
Location(s) of Use: |
Food |
|
Description: |
Flight Attendant request to view pending orders. |
|
Term: |
Visual Data |
|
Location(s) of Use: |
Display System |
|
Description: |
Raw visual information that is to be sent to end user terminals. |
|
Term: |
Web Display Data |
|
Location(s) of Use: |
Display System |
|
Description: |
Displayable web content. |
