The IASB issued IFRS 8, ‘Operating segments’, in November 2006 as part of convergence with US GAAP. IFRS 8 is similar to the US standard SFAS 131. It replaces IAS 14. It is effective for periods beginning on or after 1 January 2009, with earlier application permitted.

All entities with listed or quoted equity or debt instruments or that are in the process of obtaining a listing or quotation of debt or equity instruments in a public market are required to disclose segment information.

Operating segments are components of an entity, identified based on internal reports on each segment that are regularly used by the entity’s chief operating decision-maker (CODM) to allocate resources to the segment and to assess its performance.

Operating segments are separately reported if they meet the definition of a reportable segment. A reportable segment is an operating segment or group of operating segments that exceed the quantitative thresholds set out in the standard. An entity may, however, disclose any additional operating segment if it chooses to do so.

All reportable segments are required to provide a measure of profit and assets in the format viewed by the CODM, as well as disclosure of the revenue from customers for each group of similar products and services, revenue by geography and dependence on major customers. Other detailed disclosures of performance and resources are required if the CODM reviews these amounts. A reconciliation of the totals of revenue, profit and loss, assets and other material items reviewed by the CODM to the primary financial statements is required.

You may want to read the other chapters as well:

IFRS-1: First Time Adoption of IFRS
IFRS-2: Share-based Payment
IFRS-3: Business Combination
IFRS-4: Insurance Contract
IFRS-5: Disposal of Subsidiaries, Business and Non-current Asset
IFRS-6: Extractive Industries
IFRS-7, IAS 32 & 39: Financial Instruments
IFRS-8: Segment Reporting