scope:

The U.S. Government is developing a large number of complex systems that are required to function during or after exposure to a radiation environment. The need for these systems to accomplish their designated mission regardless of their complexity and the hostile environments that they must withstand dictates that attention be focused on hardening design techniques and hardness assurance methods used during the development and production phases of the system. While Hardness Assurance (HA) procedures are implemented during the production phase, there are HA activities that must occur during the earlier design and development phases.

When a system has a survivability requirement, specific radiation criteria are defined and hardening and HA must then be invoked by the developing agency. Hardening is the process of reducing the susceptibility of the system to a nuclear environment to acceptable limits by design and selection of parts and materials. HA consists of those manufacturing controls, lot sample tests, and screens that are applied to assure that the design hardening is not compromised during manufacturing and hence that the radiation response of all of the systems stays within acceptable limits of performance. For example, HA is necessary in parts selection to ascertain that a given part meets the established criteria, and that variations in its radiation response (whether made by one or more manufacturer), do not jeopardize the survivability of the system.

This document is intended to provide guidance to both the system development Project Manager (PM) or System Program Office (SPO) at the sponsoring agency, and the Project Manager for the prime contractor. It will assist the sponsoring agency PM or SPO in establishing survivability requirements and the needed contractual features in the Request for Proposal (RFP), the Statement of Work (SOW), and in identifying Data Item Descriptions (DIDs) for the Contract Data Requirements Lists (CDRLs) for later phases of development. The prime contractor PM will be aided by guidance in the structure and timeline of a Hardness Assurance Program (HAP), the required documentation (such as a Survivability Program Plan (SPP)), and the HA-related tasks needed as the development of the system progresses through design, development, and production phases.

To be successful, both the hardening and hardness assurance programs must be an integral part of the overall management structure. This existing structure includes design engineers, specification writers, comptrollers, purchasing, QA, value engineers, test engineers, production engineers, reliability engineers, configuration managers and others. Thus, to be most effective each of these groups must include hardness assurance as one of their responsibilities. Each (and all) of these management entities affect the ultimate nuclear survivability of the system just as they affect other aspects of system performance. All must work together as a team and HA activities must not be managed totally separate from the existing management structure. Only when survivability and HA are part of the team will they be viewed as an integral part of the program and accepted by all team members.

Even though this document will allude to various hostile environments as necessary to discuss the concept of balanced hardening, the primary focus will be concerned with nuclear and space radiation effects on electronics and the HA methods and procedures necessary to assure that the system is produced in compliance with hardness design specifications.

Because this document is intended primarily for PMs and SPOs, it does not discuss the specific details of procedures and methodologies mentioned or referenced that deal with quality control, test techniques or other such items. Instead the document is intended to:

a. Address the planning, hardening, and management approaches required at the system level to ensure that the system is produced in compliance with survivability requirements.

b. Provide guidance in defining HA activities commensurate with the threat nuclear weapon and space radiation environment and with the concept of balanced hardening to all hostile environments. These guidelines are aimed primarily at system development agencies, project managers and their contractors.

A major task in developing a system that has a nuclear or space radiation survivability requirement is the selection and qualification of electronic pieceparts to the hardness specifications. Because parts play a fundamental role in the survivability of the system, they will be mentioned frequently. However, the procedures that may be employed in the selection and qualification process will not be discussed in this document. MIL-HDBK-814, "Ionizing Radiation and Neutron Hardness Assurance;" MIL-HDBK-815, "Dose Rate Hardness Assurance;" and MIL-HDBK-816, "Guidelines For Developing Specifications for Radiation Hardness Assured Devices;" discuss in detail the HA aspects of parts selection and qualification. These details are of paramount importance because system survivability is achieved and maintained through proper specifications, the selection of adequately hard parts, quality assurance, and configuration control. However, the selection and structure of the HA activities necessary to achieve the objectives sought in this process remain a management decision.

The major objectives of this handbook are to:

a. Provide guidelines to structure a HA program addressing all phases of system development and production to ensure that the system complies with radiation hardness and survivability specifications. This HA program structure will include techniques employed at the system level as well as the HA data and procedures needed at the piecepart and other lower-tier levels. It will present the relationship of design hardening and verification to HA and Hardness Maintenance/Hardness Surveillance (HM/HS).

b. Present a description of HA activities and HA program deliverables for all phases of the program. This description will include the responsibility of subcontractors that are part of the development effort and will include tasks such as defining qualification tests, special hardware and software, and necessary documentation.

c. Show a timeline for the HA program, its major activities and its outputs.

d. Give references for existing documents that will assist in devising the HA procedures and test techniques, and in piecepart HA testing and control methods.