A commission plan is defined as an arrangement made in which people are paid based on performance.(noun)
An example of a commission plan is when salespeople are paid 10 percent of every sale they make.
The definition of a commission plan is a form of local government where a commission of elected people make the legislative and administrative decisions instead of a major and city council.(noun)
An example of a commission plan is when the department heads of a city are elected to be the group that makes the administrative decisions and determines the policies for the city, instead of a major or city council.
See commission plan in Webster's New World College Dictionary
See commission plan in American Heritage Dictionary 4