Former Management Science America executive Dennis Vohs is to join Ross Systems Inc as chairman and chief executive following a proposed management buyout at the Californian DEC VAX-based software specialists currently owned by Rossdata; the management team will receive backing from Morgan Stanley & Co, Welsh, Carson, Anderson and Stowe, as well as the Greylock Management Co which has investments in DEC; the deal is expected to be completed by the end of the month.