The new PCAOB Auditing Standard No. 7 expands the existing requirements for concurring reviews. According to the PCAOB, a well-performed engagement quality review can serve as an important safeguard against erroneous or insufficiently supported audit opinions and contribute to audit quality. The review serves as a check on the work performed by the engagement team, and the PCAOB believes it would increase the likelihood that a registered public accounting firm would identify any significant engagement deficiencies before it issues its audit report. (Source: WebCPA)
The standard is significantly more stringent than the current concurring review requirement and of course will add some more time and cost to the audits.