An apparatus and method for directing a computer system to transform a plurality of data in a planning data structure into a scheduling data structure. Each entry of the scheduling data structure has at least a start date, quantity, and duration. The method includes the steps of if the first data is a member of a cost group, setting the duration to 0 and the start date to a beginning of a month, if the first data is not a member of the cost group, determining if the first entry is new, if the first entry is new, retrieving a second data from the planning data structure, setting the quantity for the first entry in the scheduling data structure to the larger of the first data and the second data, if the first entry is at least as large as the second entry, setting the start date to a beginning of a month and the duration to approximately a month, if the first entry is smaller than the second entry, setting the start date to a date later than the beginning of the month and the duration to a value less than a month, and repeating the above steps for all the data.