The Standard Schedules Information Manual (SSIM) is published bi-annually by the
International Air Transport Association (IATA). It's a full-size softcover
book of about 450 pages describing detailed standards for the data interchange of flight schedules
Shuttling passengers and cargo around in airplanes is a huge industry
worldwide, and one that has extensive data communication needs.
These days, no airline is an island:
To successfully do business in this age of globalization, an airline must
- other airlines, usually cooperating carriers which
accept bookings for one another's flights;
- travel agencies and their providers, because bookings are
of course made against published schedules;
- airports, where flight takeoffs and landings must be managed in accordance
with airline schedules;
- government agencies responsible for flight clearances and
- air traffic control (ATC) agencies, which need to be aware of
airline's schedules in order to plan collision-safe routes for all flights;
- schedule publishers (print shops) which produce those
pocket-sized airline itineraries and other publications; and
- various intercommunicating departments within the airline itself,
for the interplay between flight planning, scheduling,
reservation, ticketing, check in,
operations, revenue management,
customer relations management, data warehousing
and so on.
To facilitate the exchange of flight schedules and other data between interested
parties, the Schedules Information Standards Committee
meets regularly to establish standards for the interchange
of such data.
These standards are documented in the SSIM.
I excerpt the SSIM's Table of Contents here, with my own abbreviations
for the chapter descriptions given in the book. Where interesting and
meaningful, I have included small examples of the material covered in the
chapters, especially the many Appendices.
Chapter 1: Definitions
Those elements of the airline industry's jargon used in the rest of the SSIM
are defined here.
'DOMESTIC FLIGHT LEG' - A flight between two stations to which the same ISO
country code applies.
Chapter 2: Information Required for Standard Schedules
The syntactic elements of a schedule are presented here and defined in alphabetical
Chapter 3: Standard Print Layouts for Schedules Information
Example layouts for printed presentation of a schedule.
Chapter 4: Standard Schedules Message Procedure
A detailed description of the format for a flight schedule updated transmitted
as a telegraph message.
Chapter 5: Ad Hoc Schedules Message Procedure
An extension to Chapter 4 dealing with so-called "ad hoc", or "occasional"
messages often used to make selective, irregular, often last minute changes
to one or more flights for a single day of operation.
Chapter 6: Airport Clearance/Advice Procedure
Used where necessary to obtain clearance or to advise of arrival/departure times.
Chapter 7: Presentation and Transfer of a Schedule Data Set
Formats and procedures for the bulk transfer of entire schedules between
Chapter 8: EDIFACT Procedures
The rules and structures for formatting schedule updates or entire schedules in
Chapter 9: Leg Schedule Message Procedure
A description of the Leg Schedule Message: A simple, leg oriented message
intended maily for use in advising schedule information to ATC authorities
and Handling Agents.
Appendix A - ATA/IATA Aircraft Types
3-character codes for every aircraft type in current use.
Boeing 747 Mixed Configuration: 74M
Appendix B - Meal Service Codes
One-letter codes representing one kind of meal served aboard a flight.
S - Snack or Brunch
Appendix C - Service Types
One-letter codes representing the type of flight service for a given flight.
J - Scheduled, Passenger, Normal Service
Appendix D - Passenger Terminals
Coding of Passenger Terminals at airports having more than one terminal.
Appendix E - Recipients of SSIM
A list of the names, titles and addresses of all recipients of the Manual. Broken
down into airline recipients, non-airline recipients, IATA offices, other IATA
groups in liaison with the SISC. The list also mentions non-Members and IATA
members who attend IATA Schedules Conferences.
Appendix F - UTC - Local Time Comparisons and ISO 2-Letter Country Codes
The time differences of all countries, or more correctly, all time zones in
the world, from UTC are given here.
UTC, or Universal Time Constant, is what used to be known as GMT, or
Greenwich Mean Time.
Appendix G - Traffic Restriction Codes Table
Codes describing restrictions on the types of operations of some flight legs.
O - INTERNATIONAL CONNECTING TRAFFIC ONLY
Carriage is limited to international online connecting traffic only;
traffic may be carried if all conditions are satisfied.
Appendix H - Explanatory Notes on SSIM Application
Useful information on how to deal with a number of subjects
Appendix I - Region Codes
Appendix K - Standard Clearance/Advice Form
- If you found the Table of Contents tedious to read through, imagine what it's like working with the actual book and its contents! I'm afraid this reflects a bit on the stuffiness of style typical of committee products.
I hear rumors that the SISC is thinking about creating an XML schema (or DTD) and associated rules for presenting flight schedule data. I'm happy to hear this, as I find EDIFACT a PITA to work with, and EDIFACT software is rare and expensive. Hooray for open standards supported by Open Source Software!
Hrrumph. Pardon me for going off on that tangent.