ASB chief Barbara Chapman will vacate her role at the end of March next year, bringing the curtain down on an almost error-free career in retail banking.At an operational level, Chapman can lay claim to having one of the most impressive records of any CEO - male or female - in the Australian and New Zealand banking markets.Whoever takes over the reins will inherit a banking franchise that is still humming after it consistently outpaced competitors on most performance benchmarks throughout Chapman's six years at the helm.During her stewardship ASB has almost doubled annual profit from NZ$560 million in 2011 to more than NZ$1 billion in 2016/17.According to recently published performance data by the Reserve Bank of New Zealand, ASB outpointed its major competitors - ANZ, Westpac, BNZ and TSB - in both returns on equity and assets for the 12 months to the end of March.ASB's net profit as a percentage of average equity was 14.2 per cent for the period, compared to 12.7 for ANZ, 12.6 for Westpac and 12.5 for BNZ.The bank also streaked the field on ROA, which came in at 1.2 per cent compared to 1 per cent for the three other banks.Of course, Chapman also deserves credit for erring on the side of common sense in managing risk across the ASB business.Unlike the company's Australian parent, ASB conducted a prudent rollout of the now controversial intelligent deposit machines (IDMs).The ASB glided through the Austrac scandal that savaged the reputation of CBA in August after it revealed that the IDMs deployed in New Zealand were programmed only to accept deposits below reportable limits set by local anti-money laundering laws.Chapman also got lucky.Her tenure as CEO coincided with a record property boom in the Auckland region where ASB enjoys a disproportionate market share in home lending compared to its competitors.Her critics say that ASB's outperformance in the last six years is mostly attributable to that boom.They also point to the fact that ASB has failed to expand strategically in New Zealand banking, particularly in market segments where it has been comparatively weak such as consumer finance and credit cards.Chapman's reign was not without controversy.Details of her remuneration package were always shrouded in secrecy by the CBA, raising questions about the group's transparency with New Zealand investors and customers.The New Zealand arms of the three other major Australian banks each disclose what their top Kiwi executives earn.The secrecy surrounding Chapman's annual pay undermined the currency of her arguments in public forums in support of equal pay for women.