“Zero defects” is an approach to manufacturing processes that emphasizes quality and conformance to standards. It’s considered part of lean manufacturing, as its end goal is to reduce waste and improve efficiency. There’s no overarching standard for zero defects. Every product and process is different, with different expectations on the part of both manufacturers and customers.
Customer expectations are the driving force behind zero defects. Through feedback and direct requests, customers determine what is, and is not, acceptable in a product or service. When a product or service meets those expectations, it can realistically be said to have zero defects. Keep in mind that every product is measured against its own quality standards -- not those of other products. Different products have different thresholds for quality, as determined by both customer and industry.
As is true in most cases, prevention is much more economical than correction after the fact. When a batch of substandard products goes out to a customer, the costs are high. There is the risk of lost business and a damaged reputation, in addition to the obvious costs of recovering and reworking the bad product. Rather than fixing mistakes, it’s much wiser to identify those aspects of a process that contribute directly to product quality (or lack thereof, when something goes wrong). It’s possible for analysts to quantify the cost of defective products, which lends support to process improvement initiatives. The Zero Defects rule stresses these initiatives as more useful and efficient than traditional QA processes.
The quality standard of zero defects should always reflect the standards of the customer. When a product is manufactured to a specification that is greater than the customer standard, it’s logical to bring that standard down a notch. Customer satisfaction is always the impetus behind the creation of specific standards. As customers’ needs change over time, manufacturers must adapt both their processes and quality standards to maintain the philosophy of zero defects.
Discussion of quality and zero defects sometimes risk straying into the realm of the abstract. To counter that tendency, quality should always be measured in terms of money. A simple acronym for expressing this idea is PONC, or the “Price of Non-Conformance.” This point of view consists of the idea that defects cost money, which is literally true. Quality inspections, defective parts, wasted materials, lost time and customer complaints are all a drain on revenue. These revenue-draining factors can be earmarked and calculated by efficiency experts. With quantitative data in hand, managers can more confidently enact process improvements that enable zero defect manufacturing.
Like lean manufacturing, zero defects is a both a mindset and an ongoing process of improvement and efficiency. It depends on a network of trust and communication between workers, management, customers and quality experts. In essence, Zero Defects is an idealized goal that organizations work toward, but never quite achieve.