“the state of performance where the technology, product, or process is minimally sensitive to factors causing variability (either in the manufacturing environment or user’s environment) at the lowest possible cost”.
His definition can be restated as making products that work the same way, every time, no matter what the condition. They must work for a very long time and still be affordable. A good working definition I once heard for optimize was:
“to make as effective, perfect, or useful as possible”.
I often have the opportunity to ask designers if their designs are optimized. They always say yes. I then ask them what they mean by the word “optimize”. They say things like, “finding a balance between cost and quality” or “making the right trade-offs”. They have entirely missed the point! Optimization does not involve trade-offs.
Whether you practice Dr. Taguchi’s methods for optimization or not, the goal for every designer should be perfection or as close to it as possible. Customers are greedy, and rightly so. Why shouldn’t they want perfection? They’re the ones spending their money on the product or service. Compromises are often necessary in product and process development, but jumping too quickly to those compromises can seriously limit your company’s growth. I once heard Akashi Fukuhara say:
“If you just meet the customer’s expectations the best case scenario is that they will only flirt with the competition, in which case, you will either lose a customer or have a reluctant repeat customer. To have excited repeat customers you need to exceed their expectations.”
Toyota has long been the benchmark for reliability in the automotive industry. Their reliability has been so good that it continuously exceeds customers’ expectations. I really thought that with the recent recall for acceleration problems on some vehicles, they would lose many of their die-hard, life-long customers. But the sales data doesn’t prove that out. I still hear people talking about how their old Toyota has 200,000+ miles and that is what they will buy next time. I wonder how many resources Toyota spends on trying to find out what is the exact mileage that their cars can start to fail, and it will be ok with the customer. I would be surprised if they spent one Yen with that type of investigation.
I believe most companies today do not understand this philosophy. They spend far too many resources trying to learn exactly what the limit will be for lack of quality before their customers complain. They totally disregard the concept of pursuing and attaining perfection in favor of discovering what they must do as a minimum to make a sale. If they put all the effort they used trying to understand exactly what that minimal level of quality their customers will accept into truly optimizing their designs, they might actually exceed their customer’s expectations, and have customer’s for life. This type of thinking is just one small aspect of the Power of LEO.