The appointment of a new head of premium business services at Commonwealth Bank is a chance for chief executive Ralph Norris and the rest of the CBA board to show their latest strategic thinking on succession planning.Norris has always said that he would like his successor to be appointed from within the ranks of the bank rather than get an outsider, as happened when he replaced David Murray in 2005.The CBA board was forced to look outside to find Norris because so many talented executives left the bank while Murray was running CBA.Since Norris took over as CEO in September 2005, there has been a significant reshuffle of management. Only three people who were on Murray's team have remained in the senior management group.Stuart Grimshaw, who was once regarded as a potential successor to Murray, resigned in September as head of premium business services after putting in solid performances in a range of different roles including head of finance and risk management and head of wealth management.The head of premium business services is responsible for CBA's institutional, corporate, business and high-net-worth personal client relationships.Normally, an executive of Grimshaw's stature would stay on the management merry-go-round and join another bank. Instead he has taken the lifestyle option and joined a boutique fund manager in Sydney called Caledonia Investments.His departure has given Norris a chance to follow the industry trend of blooding potential CEO candidates by putting them in line management jobs for several years.There are two executives who are talked about internally as potential successors to Norris but who have not had line management experience. They are: head of strategy, Ian Narev and chief financial officer, David Craig.Narev has won plaudits internally for his advice on mergers and acquisitions including one of the deals of the year, the CBA purchase of BankWest from HBOS.The appointment of Narev to run premium business services would provide a tough test of his management skills. Narev is a former management consultant but others such as Frazis have proved this is not necessarily a barrier to success in line management.Craig is said to be very ambitious but he has no line management experience. This could be the opportunity for Norris and the board to test his mettle.However, executives who have made their mark as chief financial officers seem to have great difficulty making the transition to CEO even if they are given line management experience.Former Westpac CFO Phil Chronican was appointed head of institutional banking at Westpac two years before David Morgan was replaced as part of the bank's succession planning. But Chronican did not do enough to win the top job ahead of Gail Kelly from St George.There is unconfirmed talk in the industry that Chronican was approached to replace Grimshaw but was convinced to stay at Westpac by Kelly in return for a huge pay rise.Judging from the latest Westpac remuneration table Chronican was a favoured son at Westpac in 2008. In the year to September he picked up a $2.5 million short-term cash