Commonwealth Bank is facing a potential cleanout of management positions as the board embarks on a global search for a new chief executive before the end of the 2018 financial year.On another drama-laden day for the country's largest bank, CBA chair Catherine Livingstone announced that CEO Ian Narev will vacate the role once the search for a replacement is completed. Narev took the CEO's job in late 2011.The move sparked a rally in the company's share price, which closed up 81 cents or one per cent yesterday, to A$81.31.However, banking analysts believe that valuations of the company's stock relative to major bank peers are likely to be revised as the earnings impact of the risk management and compliance breakdowns becomes clearer.CBA has traded at a premium to the other major banks on almost every valuation measure in the last three years."In the absence of positive earnings per share surprises I can't justify the price-to-earnings premium of CBA," said CLSA analyst, Brian Johnson.Against 2018 earnings estimates, CLSA currently has CBA trading on a multiple of 2.09 times net book value compared to multiples of 1.69 for Westpac, 1.63 for NAB and 1.41 for ANZ.The announcement of Narev's departure follows a bruising eleven days for the bank after Australia's anti-money laundering cop, AUSTRAC, hit the company with court action citing more than 53,000 alleged breaches.There is little doubt that the risk management meltdown in the organisation hastened Narev's exit and Livingstone sent a clear signal in her statement that the board was planning more changes."Succession planning is an ongoing process at all levels of the bank," Livingstone said in an ASX filing. "In discussions with Ian we have also agreed it is important for the business that we deal with the speculation and questions about his tenure."Today's statement provides that clarity and will ensure he can continue to focus, as CEO, on successfully managing the business."Institutional investors said they expected the board would look outside the organization for Narev's replacement because the bank now required a cultural transformation.That may even rule out the former head of CBA's retail operation, Ross McEwan, who left the company in 2013 to assume the reins of the Royal Bank of Scotland."The problem with internal succession is that it naturally creates a bias to continue the strategy of the previous chief executive," said Johnson."And that's a real problem."Johnson said several AUSTRAC allegations were "deeply concerning".He highlighted paragraph ten of the concise statement of claim as containing one of the most worrying of the alleged breaches.The regulator alleges in that paragraph that CBA submitted late notifications for six high value transactions on five customers who were identified by the bank as posing a potential risk of terrorism financing. If this allegation was found to be true by a court then it means the bank was late reporting two threshold transactions for one customer that it suspected of having links to terrorism.The controversy took a heavy toll on senior executive remuneration in the 2017 financial year.Livingstone's decision to reduce