Parts, Materials, and Processes Engineering in the Early Stages of Program Execution

Book iconFirst published May 2013, Crosslink® magazine

Electronic hardware—electrical, electronic, electromechanical, electro-optical—parts, materials, and processes (PMP) are fundamental to mission reliability and program success. Just as dependable space operations rely on robust designs, electronic hardware designs depend on robust PMP to ensure that elements have been fully screened and qualified for long life as well as for tolerance of the harsh environment of space. Similarly, the characteristics, performance, and requirements of a program’s PMP must be well understood by the space system design team to preserve any inherent robust capabilities. The Aerospace Corporation’s PMP engineering department is a critical resource and process with distinct activities throughout all phases of space system acquisition, ensuring program and mission success.

Much activity is performed in the early stages of space system acquisition. During concept studies (phase 0), Aerospace helps to develop the PMP language used in requests for proposals or statements of objectives. Aerospace also reviews contractor proposals, participates in source selection, and reviews or helps develop any tailoring to baseline PMP requirements that are unique to a program. Aerospace’s expertise and experience in PMP engineering and its insight across programs, contractors, and the supply base have been used to develop a common set of appropriate program requirements for space PMP. These requirements form the basis of PMP rigor for a program and have a significant benefit on the cost, schedule, and reliability of a given space system. For example, higher-quality space parts mean higher and longer reliability; and sound mission assurance practices reduce part failures during production, system and spacecraft testing, and operations, thus reducing total lifecycle costs.

In the concept development (phase A) PMP engineering helps provide inputs to the development of system requirements documents, verifies that the contractor’s PMP control program plan defines necessary tasks and is consistent with mission and contract requirements, and verifies the contractor has organized a PMP control board per required policies. The control board is a formal contractor organization established to manage and control the selection, application, procurement, qualification, and inspection of PMP in accordance with the program requirements.

Phase A is the stage when evaluations are conducted relative to top-level PMP requirements as part of the systems design review. This is also the stage for verification of the flow-down of requirements to subcontractors, reviews of new technology, and qualification planning for insertion into new and existing programs. Aerospace has developed a set of guidelines for technology insertion that assist in this activity. This is appropriate for PMP that have not been qualified for application with-in the specific space environment, or for those that have undergone changes that may alter the performance, functionality, or reliability of spaceflight hardware. The document is intended to provide guidance to the government, program managers, and technology insertion boards for an understanding of the total magnitude and effort required to evaluate necessary areas of concern. Aerospace has assisted in the incorporation of this concept and requirements into MIL-PRF-38535, the military standard for integrated circuits, to ensure the quality and reliability of new technology.

During preliminary design (phase B), which is followed by the preliminary design review, PMP engineering evaluates the contractor’s preliminary design PMP process, contractor and subcontractor control plans, and radiation assurance plans for adequacy and adherence to the tailored PMP requirements and processes in accordance with program requirements. Aerospace engineers also participate in PMP control board and control functions. This activity is the key management process for PMP risk management, and is where Aerospace plays a critical role, especially when contracts have acquisition and government approval authority. For example, Aerospace reviews the contractor data products in accordance with the control plan, such as characterization data, preliminary approved parts and materials selection lists, and PMP approval of nonstandard approval requests. In addition, Aerospace reviews new technology insertion plans and tests, ensures consistency of PMP across subcontractors, reviews stress and end-of-life derating, evaluates contractor test and qualification plans, and reviews test data as it becomes available. These reviews are valuable in the early detection and prevention of reliability-suspect PMP and inadequate test and qualification programs that could result in higher costs and risks to the schedule and mission from part failures during system tests and operations.

PMP engineering must work closely with design engineering to prevent selection of parts and materials that are not readily available at the quality and reliability levels required for the mission as specified in the control plan. The designer’s choice of technology during this phase de-termines subsequent cost, schedule, and reliability of the end system. For example, use of commercial-off-the-shelf parts designed and manufactured for the commercial market may have unique failure risks depending on the technology and application. These parts typically reduce the reliability of the system and require special qualification, screening, and radiation test programs, which can drive costs and affect the schedule. Thus the program-approved selection and as-designed PMP lists should be independently reviewed to identify and manage risks early in the program.

Independent from specific activities performed during the acquisition execution of a program, PMP engineering performs a variety of functions related to the maintenance and improvement in the industrial base and to specifications and requirements used for each PMP technology. Aerospace partners with other government agencies to participate in auditing the industrial supply base to ensure products are being manufactured according to their space requirements and leads information-sharing forums and working groups such as the annual Space Parts Working Group conference. Aerospace and its partners also operate alert systems, such as the PUMPS (parts, units, materials, processes, and subsystems) problem-alert database for cross-program sharing of issues and common problems. This prevents issue proliferation, helps to determine impact risk across programs, and facilitates issue solutions. Aerospace laboratories also perform independent research and reliability studies to better understand and reduce risks with new technology insertion planning for space systems. For example, Aerospace has led a study to determine the reliability and risk of a particular field-programmable gate array technology, performing extensive physical analysis and long-term reliability life testing.

Aerospace also helps to develop and review new test methods and standards to ensure product reliability and incorporate lessons learned into the methodology. For example, Aerospace helped to facilitate a cross-program and contractor solution to a radio frequency attenuator issue by implementing a new test and screening at the parts level to identify and prevent a suspected product from entering flight hardware. This solution was later incorporated as a new revision to the military requirements standard used to procure the technology. Three of the latest requirements specifications being published—following extensive industry reviews—are revision B to the two Aerospace PMP program requirements documents covering the PMP control program and detailed technical requirements, and a photonic device standard to be published by Aerospace and the Defense Standardization Program Office, Office of the Secretary of Defense.

A wide range of skills and knowledge bases is required to support these PMP activities. These include an in-depth understanding of applicable military standards for various types of PMP and their associated standard testing methods, and a thorough understanding of the underlying technologies and their applications, including hardness assurance requirements. A comprehensive understanding of the related industrial base is needed to ensure the lowest-risk part or material is selected that meets system performance needs. Similarly, manufacturing engineers are required to select low-risk, qualified reliable processes for which a team of technical specialists is needed. Aerospace plays an important role in providing the necessary resources and expertise for helping assess and supplement the depth and breadth of the government and contractor PMP engineering team.

Further Reading

Aerospace Report No. TOR-2006(8583)-5235, “Revision A, PMP Control Program for Space and Launch Vehicles” (The Aerospace Corporation, El Segundo, CA, 2006).

Aerospace Report No. TOR 2006(8583)-5236, “Revision A, Technical Requirements for Electronic PMP Used in Space and Launch Vehicles” (The Aerospace Corporation, El Segundo, CA, 2006).

Aerospace Report No. TOR 2007(8546)-6018, “Revision B, Mission Assurance Guide, Chapter 15, Parts, Materials and Processes,” pp. 335–355 (The Aerospace Corporation, El Segundo, CA, 2007).

Aerospace Report No. TOR-2012(3909)-16, “Optoelectronic Device Qualification for Extreme Environments” (The Aerospace Corporation, El Segundo, CA, 2012).

– Steven Robertson, director, Parts, Materials, and Processes Dept.

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