The weights engineer is required to provide a figure of merit to management for conceptual, preliminary, and final design. Now he is faced with a demand from management and the customer to produce that figure of merit for a large number of geometric configurations and program (mission) variables particularly in the conceptual and preliminary stages. This paper presents a solution in terms of a Preliminary Design Analysis Program (PDAP) developed by the McDonnell Douglas Astronautics Company weights organization to provide both weight and sizing data. The paper also expresses the philosophy that the program is a simple extension of the weight engineer's daily activity.