EDIFACT / ONU message Design Guidelines (CAN mixte / ONGC-200,27 à 91)

General Introduction

One of the key requirements before organizations can exchange administrative, commercial and transport information between their computers, without manual intervention, is agreement on the content and structure of the information to be transmitted.

In EDIFACT, this is achieved by developing United Nations Standard Electronic Messages (UNSM's), for both national and international use.

These guidelines are intended for:

(a) those who want to submit a draft message for registration as a new UNSM. To achieve this status:

- the proposed draft message must be for use at the international level (rather than solely for use at a National or Sectoral level);

- there must be no existing UNSM having a function identical (or nearly identical) with the proposed draft; and

- the proposers of the draft need to accept that if there is int erest in the proposed message amongst other potential users in other sectors and/or countries, those users will wish to take part in and contribute to the development.

(b) those who wish to propose an amendment to an existing UNSM by means of a "Change Request". (The procedures for maintenance, change requests and technical assessment will be found in Appendix 4 to these guidelines.);

(c) those who wish to design standard messages which do not qualify for UNSM status. (These could include messages for use at an international level, but only within an identifiable sector - for example a specific industry. Similarly, messages for use only in National applications - which could, for e xample, be for National Customs systems; and for messages designed for Private Sector applications.)

The guidelines have several goals:

- to introduce the EDIFACT Syntax Rules for those who have not encountered them earlier;

- to propose a uniform technique for the development of standard messages for use at different levels and in different applications;

- to recommend a standard layout and presentation for documentation specifying EDI messages;

- to recommend consistent techniques for designing new messages, or for modifying existing messages.

The guidelines relate to work carried out by the United Nations Eco nomic Commission for Europe, Working Party Number 4 (UN/ECE/WP.4) and the International Standards Organization (ISO), known as EDIFACT (Electronic Data Interchange for Administration, Commerce and Transport).

It is essential that newcomers to the EDIFACT standards should familiarize themselves with the supporting documentation available (see Section 1), and in particular with the rules for Syntax - which govern the presentation of EDI messages for computer processing.

Throughout this document, the word "message" has a meaning identical to "transaction message" and "transaction set", terms previously used in other EDI documentation.