Solution
Based on the criteria set in IFRS 15, a performance obligation is satisfied over time if any of the following criteria are met:
In the case of AFS Limited, the third criterion is applicable. The performance of AFS Limited doesn't create an asset with an alternative use as the audit services are specific to the client, WBC Limited. Furthermore, AFS Limited has an enforceable right to payment for the work done to date as specified in the contract terms, which would include costs plus a reasonable profit margin if the contract is terminated early for reasons other than AFS Limited's failure to perform as promised.
Therefore, AFS Limited's performance obligation is satisfied over time and they should recognize revenue accordingly over the term of the audit contract.