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 Establish a reliability goal and use it to determine reliability budgeting.

 Quantify the use environment. Use industry standards and guidelines when aspects of the use environment are common. Use actual measures when aspects of the use environment are unique, or there is a strong relationship with the end customer. Don't mistake test specifications for the actual use environment. Clearly define the median and realistic worst‐case conditions through close cooperation between marketing, sales, and the reliability team.

 Perform assessments appropriate for the product and end‐user. These assessments require an understanding of material‐degradation behavior, either by test to failure or by using supplier‐provided data. The recommended assessments include:– Thermal stress– Margin or safety‐factor demonstration (stress analysis that includes step stress tests (e.g. HALT) to define design margins)– Electrical stress (circuit, component derating, electromagnetic interference [EMI])– Mechanical stress (finite element analysis)– Applicable product characterization tests (not necessarily verification and validation tests)– Life‐prediction validation (accelerated life test [ALT])– Mechanical loading (vibration, mechanical shock)– Contaminant testing

 Perform design review based on failure mode (DRBFM, Toyota methodology). This readily identifies CTQ (critical to quality) parameters and tolerances and allows for the development of comprehensive control plans.

 Perform Design for Manufacturability (DfM) and Design for Reliability (DfR) and involve the actual manufacturers in the DfM process.

 Perform root cause analysis (RCA) on test failures and field returns to initiate a full feedback loop.

Best‐in‐class companies have a strong understanding of critical components. Component engineering typically starts the process through the qualification of suppliers and their parts. They only allow bill of materials (BOM) development using an approved vendor list (AVL). Most small to mid‐size (and even large) companies do not have the resources to assess every part and part supplier. Those who are best in class focus resources on those components critical to the design. Component engineering, often in partnership with design engineers, also perform tasks to ensure the success of critical components. This includes design of experiments, test to failure, modeling, supplier assessments, etc. Typical critical component drivers are:

 Complexity of the component

 Number of components within the circuit

 Past experiences with component

 Sensitivity of the circuit to component performance

 Potential wearout during the desired lifetime

 Industry‐wide experiences

 Custom design

 Single supplier source

From the component perspective, reliability assurance requires the identification of reliability‐critical components and drives the need to develop internal knowledge on margins and wearout behaviors. RCA requires the true identification of drivers for field issues combined with an aggressive feedback loop to reliability and engineering teams and suppliers.

Best in class companies provide strong financial motivation for suppliers to perform well by creating agreements with the supply chain to accept financial incentives and penalties based on field reliability. These practices allow companies to implement aggressive development cycles, proactively respond to change, and optimize field performance.

Establishing a successful, comprehensive reliability program requires planning and commitment. Requisite priorities include:

1 Focus: Reliability must be the goal of the entire organization and must be implemented early in the product development cycle. Separate reliability from regulatory‐required verification and validation activities and mindset.

2 Dedicated staffing: Assignment of responsibilities without assigning resources risks failure.

3 Clearly define reliability goals and the use environment: these drive the rest of the reliability program.

4 Identify critical components, especially those at risk of wearout. Initiate test‐to‐failure and design‐ruggedization activities.

5 Implement step‐stress testing at both sub‐assembly and assembly levels.

6 Perform RCA. Focus on the top three field issues, and repeat; drive to quality assurance as appropriate.