Today’s advanced product development tools and processes go a long way in helping to ensure product quality. Finite Element Analysis (FEA) and simulation allow components, assemblies, sub-assemblies, and even entire systems to be analyzed for manufacturability, durability and quality in the early upstream stages of product development – well in advance of manufacturing. However, even the best designed and painstakingly manufactured products are not immune to problems. Consequently nearly all manufacturers have implemented quality safety nets to capture noise, vibration and other quality issues before products reach the customer.

This level of quality control often involves a manual parts inspection at the end-of-production. While some implement 100% part inspection others are content to do random spot checks. So what’s the problem?  Too many companies continue to rely on the discretion of a quality inspector leading to a subjective interpretation of acceptable quality – subjective decisions that are rooted in emotion and may or may not agree with the customer’s interpretation of quality. Too often quality is more of an art than it is a science; and standards can vary widely.

Real World – Real Challenges

While design and simulation tools have clearly taken the product development process and product quality to new levels, there remains a real need for physical science-based validation. Manufacturing, assembly, and design imperfections can manifest into expensive quality issues including mounting customer complaints, recalls, excessive warranty claims, and lost market share and contracts. It’s therefore increasingly important to verify that all final products meet quality standards prior to reaching the customer.

From automotive and appliance to medical, transportation and beyond, original equipment manufacturers across industry generally have an extended list of suppliers.  And for OEMs, the quality of components and sub-systems their suppliers provide is absolutely critical. “Consumers rarely differentiate between the system and its components. Sub-system flaws generally create overall negative feelings toward the system as a whole,” said Christopher Kus, Project Engineer and NVH Expert for the Automotive Seating Business Group-NAO of Faurecia. “For example in the case of an automobile, a rattling window, unreliable ventilation fan or noisy seat motor will result in a reputation for poor quality for the entire vehicle; not just that particular sub-system.”  Because their reputation is at stake, along with market share, OEMs are extremely particular about suppliers. If you can’t meet quality standards and deliverability schedules, they will find someone who will.

As a global leader in automotive technology, Faurecia Seating develops and produces seat systems that optimize the comfort and safety of occupants while offering premium quality to its customers. It develops innovative solutions for thermal and postural comfort, health and wellness and advanced safety for the use cases of today and the cockpit of the future.  By quantifying and qualifying quality Faurecia is able to meet and exceed the expectations of its customers – and indirectly with their customers.

“Throughout manufacturing there’s no time for detailed laboratory quality testing. As a result companies generally rely on a Pass/Fail or Red Light/Green Light inspection process,” explained Kus. “To get to that point we take subjective, often vague, input from the customer to create objective quantifiable metrics. We begin with subjective jury evaluations to determine a rating of specific noises.  From the results we can use statistical methods to choose what psychoacoustics best can be used to describe how the human ear perceives these sounds of the specific sound source.  From there we use statistical methods to create an algorithm to correlate to the rating system of the human ear subjective ratings.”

Removing human subjectivity from the equation is critical. “For example, supplier requirements might call for the product to satisfy a number of specific design and performance parameters and be free of other objectionable noises. Noise and vibration quality levels should not be left to human emotion. What’s unacceptable one day might be accepted the next; depending on any number of circumstances or how the individual feels on that particular day.”  All reputable manufacturers implement some sort of quality assurance. But if quality is open to interpretation they are headed down a dangerous road.

Next up: Automating Objectivity