Estimates with significant measurement uncertainty — risk assessment and substantive procedures.
To obtain sufficient appropriate audit evidence about whether accounting estimates and related disclosures are reasonable.
SA 540 sits in the Audit Evidence phase of the audit. The Standards on Auditing are issued by the ICAI Auditing and Assurance Standards Board (AASB) and deemed to be prescribed by the Central Government under Section 143(10) of the Companies Act 2013. Compliance with SAs is mandatory for every audit conducted by a Chartered Accountant in India.
For authoritative text, refer to the ICAI AASB Compendium of Standards on Auditing at icai.org.