Determining a particular product mix of old and new products to either minimize stranded inventory of old unique sub-components composing the old product or to minimize cost savings by phasing out the old unique sub-components of the old product is described. When a new product costs the same or more than the old product, a product mix which minimizes stranded inventory is determined. To this end, a liability on inventory of old unique sub-components at a number of build out quantities including the total number of product units to produce is determined. Additionally, a number of old products to produce is selected to correspond to a point where the liability on inventory of old unique sub-components is constant between consecutive build out quantities in order to reduce stranded inventory. When a new product costs less than the old product, a product mix which maximizes cost savings is determined. To this end, a liability on inventory of old unique sub-components at a number of build out quantities including the total number of product units to produce is determined. An economic buildout plan which indicates cost savings resulting from replacing the old product with the cheaper new product at the number of build out quantities including the total number of product units to produce is also determined. A number of old products to produce is selected to correspond to the maximum cost savings as indicated by the largest value in the economic buildout plan.