The implementation of finite sequential machines by using a programmable array logic to synthesise their combinational part is considered. A critical view of the efficiency of existing methods to carry out the state assignment of these machines is given, and it is shown that we can derive a bound on the number of state variables beyond which even an arbitrary coding usually leads to better results in terms of area occupation. It is suggested in the paper that this bound can still be found when more refined area estimates are used. register