1. A method for generating an optimized pricing plan, comprising: accessing a hierarchy comprising a sequence of levels, each level comprising an objective function and a set of constraints associated with the objective function; determining a mathematical programming model representing a pricing plan problem for an item group comprising a plurality of items, the mathematical programming model comprising a set of initial constraints; repeating for each level of the sequence of levels: selecting a level comprising an objective function and a set of constraints associated with the objective function; adding the set of constraints associated with the objective function to the set of initial constraints; optimizing the mathematical programming model to yield an optimized boundary for the objective function; and adding a constraint generated from the optimized boundary to the set of constraints of a next level; optimizing an objective function of a last level of the sequence subject to the set of constraints associated with the objective function to yield an optimized result, the set of constraints comprising a constraint generated from the optimized boundary of a previous level; and generating an optimized pricing plan in accordance with the optimized result, the optimized pricing plan associating a price with each item of the item group.