In this paper,the BFA model is extended to solve th e problem that the BFA model cannot exp ress weighted voting in a straightfo rward manner. and meanwhile all prop-erties in the BFA model are still held.

• 对BFA模型进行了扩展；解决了BFA模型不能直接表达职责分离中带权表决的问题；同时扩展的BFA模型仍然具有BFA模型的所有特性.