Several years ago, when I was visiting an apparel factory in Asia, I witnessed a manufacturing mix-up. Because of an error during a dyeing process, the factory had produced thousands of shoes with blotchy, purplish soles instead of pink soles. Of course, this isn't a unique situation in manufacturing. When you're dealing with complex systems operating in an even more complex world, you can't completely eliminate errors. Every day, companies discover errors in finished products, from material defects to error-laden labels. Understandably, businesses don’t want defective products on the market. Defects can pose a signficant risk to brands whose reputations are built on delivering safe, high-quality products. Even functioning products with cosmetic defects, like the shoes with blotchy soles, can pose financial risks. If a defective product is unmarketable - if there's no demand for it - it doesn't make sense to sink more money and resources into packaging, shipping, warehousing, and using retail space for it.
So, millions of tons of fuels and other material resources are used to reprocess defective products. Responsible companies expend considerable effort to recycle the resources in these products. But the later in the manufacturing cycle problems occur, the harder recycling is and the more expensive it becomes. Materials that are fused and bonded together have to be separated and the value of the components can be severely degraded from impurities caused by mixing.
Recovering materials has an ecological impact, too. Recycling, especially recycling finished products with multiple materials, uses a lot of energy. Moreover, because the quality of the recovered materials is usually lower than that of the original, the materials are employed in lower-grade uses, while even more resources are needed to replace them in their originally-intended destination. This permanently reduces the availability of high-quality, concentrated reserves of the raw materials that make up industrial products.
What's the solution? Reducing waste associated with errors will result in part from measuring the final, corrected embodied mass per product unit delivered - including all inputs, regardless of whether they appear in a final product or were "lost" or reprocessed along the way - against the real value delivered. In this case, value delivered has to do with the benefits to customers from the shoes that are sold, such as the number of injury-free miles run or hours played. This benefit needs to be weighed against all of the resources used in the process of bringing those shoes to market, including the resources used to manufacture and reprocess any defective shoes. Companies that measure and strive to improve the relationship between resources used and value delivered will find that this will help illuminate the cost of errors and eventually reduce errors and the resource use associated with them.