The system specification in the definitized contract for full-scale development is the foundation for the design, test, and manufacture of a weapon system. The clear expression of requirements in the contract is an essential objective of the government and the contractor in communicating the needs for a project. To ensure that this is met, requests for proposals must be explicit in transmitting project intent and philosophy, and in establishing underlying objectives, particularly with respect to the priority and relative weighting of full-scale development requirements. Project schedules established in the requests for proposals must realistically reflect the time required to achieve the objectives intended for the project. The timing of program phases must accurately acknowledge the time required for each specific activity if early development of mature systems is expected.
Cost studies have shown that a significant portion of development costs results from poor or premature decisions made at higher levels of design. It is important that requirements be delineated in both quantitative and qualitative terms of progressively lower levels of details as the product development cycle unfolds. Although it is true that any new system contains resources developed and/or used in older systems, beware of means dictating requirements. Requirements should always precede functional or physical means, which should then be designed or selected to satisfy the requirements.
The design requirements for full-scale development must be specifically defined to meet the mission profile, beginning with factory acceptance and extending throughout the life of the system. These requirements include a complete definition of the total range of environments to which the weapon system will be exposed, including conditions of storage, maintenance, transportation, and operational use. The system specification must define the total envelope of external environments, and the contractor must augment these as required to define his system's internal environmental conditions that become the design criteria for the component parts of the system. Operational requirements, from which design requirements are derived, are of no direct value to system designers. It is the responsibility of the government to specify the design requirements which will satisfy the operational requirement.
Design requirements include a full and explicit statement of quantitative performance requirements. In addition to the more obvious requirements for system performance levels, this set of parameters includes structural static and dynamic requirements, weight, reliability, maintainability, and unit production cost. To ensure affordability, specified levels of reliability and maintainability must be consistent with realistic expectations of achievement within the limits of existing technology. The requirements must be defined in terms relevant to the contractor (e.g., mean time between failures and mean time to repair) and should all or for growth during the project.
When the achievement of specific quantitative system requirements is conditional upon the performance of a set of predefined tasks, the contract must establish the requirements for development of approved program plans for the accomplishment of these tasks. This will be the case in such disciplines as a structural analysis, weight control, stress analysis and derating criteria, systems safety, corrosion prevention, parts standardization, and similar activities. The contract clarifies the government's intention with respect to the conduct of these programs, and the specific requirements for each are tailored to the needs of the weapon system development project. It is appropriate for the system specification to be as explicit (and as lengthy) as necessary to ensure an unambiguous explanation of these requirements.
At each level in the contractual hierarchy, a significant fraction of the development and production funding (often greater than 50 percent) is expended in the form of procurement from suppliers. It is essential to the achievement of satisfactory design that the project management philosophy and project objectives are adhered to at all levels in the contractual process. Detailed instructions and requirements should flow down from each procurement level to the next to whatever degree is necessary to ensure this top-to-bottom consistency. The requirement for flow down is an integral part of the basic prime contract.
Besides the more obvious performance and reliability requirements, there is the additional demand of producibility: it must be economically feasible to manufacture a quality product at a specified rate and to deliver end items capable of achieving the performance and reliability inherent in the design. This design requirement is not always well understood and historically has taken a back seat to more popular objective of high performance. The results of this neglect have ranged from factory rework rates in excess of 50 percent to suspension of government acceptance of end items pending major redesign for producibility. A strong producibility emphasis early in design will minimize the time and cost required for successful transmission to production.
Producibility considerations require inclusion of the following requirements in the system specification and in its execution by the contractor:
a. Design engineers have manufacturing knowledge or experience
b. Design policy includes producibility
c. Manufacturing engineers are involved early in the design process
d. Engineering is involved in developing the manufacturing plan
e. Detailed design documents require review by manufacturing
f. Released engineering documents require sign-off by manufacturing
Requirements of joint engineering/manufacturing participation throughout the full-scale development phase are among the most critical to ensuring that the risk attributable to transmission from development to production is minimized.