A method of operating a computer system includes storing, in the computer system, a database containing performance measure data regarding performance measures of a plurality of items. The method further includes inputting into the computer system a plurality of performance measure constraints. The method also includes modeling the performance measure constraints with a set of equations. The equations include a plurality of variables. Each of the variables corresponds to a respective one of the items. Each variable is, for example, to be assigned either the value “1” or the value “0”. The value “1” may represent a recommendation to take an action relative to the corresponding item in the portfolio and the value “0” may represent a recommendation to take another action. The computer system is used to solve the set of equations to generate one or more solutions that satisfy the performance measure constraints.