GS1 standards that define interfaces facilitate interoperability between different system components deployed by end users. They are typically specified in three layers. All standards in the Share layer, as well as some infrastructure standards in the Capture layer, are designed in this way.

A fundamental architecture principle of the GS1 system is that each end user retains control over the data it originates. However, certain types of data are logically aggregated across many different end users. An example is master data in the Global Data Synchronisation Network, where each end user can synchronise master data for trade items identified by their Global Trade Identification Number (GTIN), regardless of the originator.

GS1 standards for business data and communication provide the means for two end users to share business data reliably, once they have identified each other. GS1 standards for data and service discovery exist to help end users identify each other.

In general, there are four ways that one end user might identify sources of data owned or maintained by other end users:

GS1 standards offer several methods for communication of Business Data between end users. In summary, the methods are:

■ “Push” methods, where one party unilaterally transfers data to another in the absence of a prior request. Push methods may be further classified as:

□ Bilateral party-to-party push, where one party transfers data directly to another party

GS1 standards for business data pertain to three categories:

■ Master data that provide descriptive attributes of entities identified by GS1 identification keys, including trade items, parties, and physical locations.

■ Transaction data that consists of transactions related to business processes across the value network.

This section discusses the architectural foundations underlying GS1 standards for business data sharing.

From a GS1 perspective, we can distinguish three types of data carriers, (see Table 5‑1). According to the categorisation below, only data carriers belonging to ‘Type A’ are considered global AIDC data carrier standards, (e.g., EAN/UPC, GS1 DataBar, GS1 2D, 2D (GS1 Digital Link URI), or UHF EPC/RFID).

GS1 defines GS1 identification keys and AIDC data in a data carrier-neutral way so that their semantics are the same regardless of which data carrier, or electronic messaging, is used.

Figure 5‑4 Four AIDC data carriers encoding the same GTIN value 9506000134352

GS1 automatic identification and data capture (AIDC) applications originates when a device (e.g., scanner, RFID reader) determines that an AIDC data carrier is carrying GS1 identifiers or AIDC data. This workflow occurs between the scan or read of the AIDC data carrier and the use of the scan/read of the GS1 identification key or AIDC by the application.

The purpose of AIDC data carriers in the GS1 system is to provide a reliable way to automatically capture a GS1 identification key to link to the data held on computer systems as part of a workflow. In addition to the GS1 identification key, AIDC data (e.g., expiration date, weight, sensory data) may also be a part of the workflow. In a GS1 compliant application of AIDC data carriers, a GS1 identification key must always be present.