Jorge Alberto Diaz
Across many applications within the manufacturing industry, we encounter regulations, guidelines and certifications that closely manage the way we maintain a proper QMS (Quality Management System), customer satisfaction, or simply reduce variation across the supply chain. Examples include ISO 9001, ISO 13485 for medical devices, IATF 16949 for the North American automotive industry and AS9100 for the aerospace sector. Those standards help all of us, as leaders in the manufacturing domain, to maintain standardization, proper documentation and the highest levels of consistency in our day-to-day operations. Regardless of which department in particular we work in — Quality, Test, Reliability, Process Engineering, Production Planning or execution — we all are tied by these similar practices independently of the industry application, and the answer to the question “Why?” is simple. It’s because these methodologies have consistently demonstrated their ability to reduce variation, enhance product quality, improve process control, and support scalable manufacturing operations across a wide range of industries. Some companies like AIAG, or better known as the Automotive Industry Action Group, have gone further in this space to provide multiple tools, training and a space to connect with other industry leaders, share ideas, methods and a path to standardize supplier quality.
Some of the most widely adopted methodologies, frameworks, and quality tools developed from multiple efforts over the last few decades, and still in use today across the manufacturing industries, are FMEA, Lean Six Sigma, APQP, PPAP, MSA & SPC, Kaizen, etc. Based on our training, we are typically drawn to think that all of those tools only apply to the products that we are fabricating — a Wi-Fi router, a cellphone, a data server, a car’s transmission, an audio amplifier, a medical respirator, ADAS systems, electric motors, wearable gadgets or Battery Management Systems. All those products have something in common; they are made in a typical manufacturing assembly line that follows the same principles, “Delivering products efficiently, consistently, and at scale while maintaining the highest achievable levels of quality, reliability, and repeatability.” This is the main reason why all of those tools apply to multiple industries. While these methodologies are traditionally associated with product manufacturing, many of the same principles can be equally valuable when applied to the design, development, deployment, sustainment and improvement of Manufacturing Test Systems.
“Test systems are no longer simple support equipment hidden behind the manufacturing line.”
If we take APQP (Advanced Product Quality Planning) as a core departure point, it is based on 5 phases + an improvement loop. Those are Planning, Product Design & Development, Process Design & Development, Product & Process Validation, and Production, with a feedback assessment and corrective action loop that spans across all phases.
Taking Phase 1 as an example, “Planning,” during this phase APQP leverages key inputs including Voice of the customer, Market research, Business & Marketing plans, Product or Process Benchmarking and Reliability studies. The point of this phase is to evaluate where this product is going to be positioned in the market, what is being created and how this will be used by the end customer, and what the potential sales & market opportunities are.
Applying the same principles to our test systems allows us to establish “Design for Testability” (DFT) practices early in the product lifecycle. These practices guide product design decisions that enable effective Manufacturing, Reliability and Validation Testing. Deep in the product conceptualization & design phase, we can ensure that the Electrical Design of PCBAs considers the proper rules for Test Point Access, Space clearance between components, TPs or tooling holes, Alignment, Strain gauge & Finite Element Analysis (FEA) planning, tolerance stack-up, Monte Carlo Simulations, and potential DPMOs to be observed on this product based on the components used, the manufacturing process, etc. During this phase we can implement checklists for EE’s or ME’s who are designing a product to achieve specific functionality, to provide them with proper guidance to ensure such design will also be “Manufacturable” (DFM), “Assemblable” (DFA), or “Testable” (DFT). In that way, we can name Phase 1 “Test Planning.”
Applying the same thinking to the other phases, we can develop a full “DFT Lifecycle,” converting APQP phases into DFT phases as shown in the image below, where we also maintain a loop of improvements where core methodologies like problem solving, error proofing and Six Sigma can be maintained; a space where we monitor capacity, scalability, and supplier management, while also providing a space to fully embed MSA & SPC to continuously monitor to prevent, correct or improve performance in manufacturing standardization and consistency. Metrics and controls such as Cpk, FPY, 2PY (Second Pass Yield), OEE, Calibration compliance and measurement correlation studies, etc., are perfect cases of what should always be in control for a Test Station to operate reliably during its usable life.
Test systems are no longer simple support equipment hidden behind the manufacturing line. They have become critical assets that directly impact quality, scalability, traceability, and customer satisfaction. As manufacturing technologies continue to evolve, organizations that manage their test systems with the same discipline applied to their products will be better positioned to achieve consistent and sustainable operational excellence.
Beyond my day-to-day work, I continue to study and promote the application of quality management principles to manufacturing test engineering. If your organization is exploring Design for Testability, APQP for test development, MSA implementation, or broader test lifecycle management strategies, I would be delighted to exchange ideas and lessons learned with fellow practitioners.
