1. A method of validating work packets within a software factory, the method comprising: creating a preliminary work packet, wherein the preliminary work packet is a self-contained work unit that is assembled with other work packets in an assembly line within the software factory to create a customized deliverable software product; appending a validation constraint to the preliminary work packet to create a constrained work packet, wherein the validation constraint is a performance constraint that must be satisfied before the preliminary work packet is permitted to proceed to a next construction step, wherein the next construction step further processes the preliminary work packet; submitting the constrained work packet to the software factory; validating the validation constraint found in the constrained work packet to create a validation result, wherein validating the validation constraint confirms that the validation constraint is proper for the constrained work packet at a specific stage in the software factory; storing the validation result for the constrained work packet in a validation history database; in response to the validation result failing to meet all requirements of the validation constraint for the specific stage, resolving the validation constraint and re-submitting the constrained work packet to the software factory; in response to the resolving of the validation constraint causing the constrained work packet to meet all requirements of the validation constraint for the specific stage, optimizing the constrained work packet for future executing by appending all validation constraints, which were generated during the resolving step, to the constrained work packet to create an optimized final constrained work packet; and delivering the optimized final constrained work packet to a final stage in the software factory for final execution, wherein final execution assembles the optimized final constrained work packet with the other work packets in the assembly line to create the customized deliverable software product wherein the optimized final constrained work packet constitutes a contractual agreement that governs a relationship among a design center, a software factory governance board, a software factory operations unit, and the assembly line in the software factory, wherein the design center breaks a software project into major functional areas, wherein the software factory governance board determines whether or not to allow the software factory to accept the software project, wherein the software factory operations unit dispatches the software project to the assembly line, wherein the assembly line receives and executes work packets that are specified by the design center to create the customized deliverable unit of software, wherein each of said work packets further comprises an exit criteria, and wherein the exit criteria is a checklist for returning said each of said work packets from the assembly line to the software factory operations unit and for returning the customized deliverable unit of software from a customer to the software factory.