As you already discussed, quality's a very important factor that determines utility, and therefore it is a very critical element in determining the value. Then the question is what happens if quality fails. In other words can we think about what happens when, you know, quality fails, in other words, the quality's not satisfactory and the customers is not happy. [BLANK_AUDIO] Obviously, the company must make a great effort to improve quality. In other words, there are some internal efforts for quality improvement in order to eliminate, in order to eliminate quality failures. And we will make two distinctions. Internal quality failure and external quality failure. How? So relatively straight forward, let's say this is time, and this is point of a purchase. In other words, this is where the customer buys or purchases the product or service. In other words this is internal to the company, and this is external. Right? So if the company identifies something wrong in its product's quality, that's internal quality, internal quality failure, internal quality failure. Whereas, if the quality problem is discovered by the customer, or by, or in the market, then we call that as external. External quality failure. So there are many costs related with this quality failure. For instance, let's say what are the internal quality failure costs? If you identify, if you identify your defect, your defect, the defect of your product before you actually sell your product in the market then you probably needed to do work, in other words you needed to, you know, you work again or you probably want to prepare something or even you want to scrap the defect completely. So there are these kind of costs. The other thing, what happens if the defect is discovered by the customer and the product fails outside the company? And I want to think about two different types of costs. For instance, your short term costs. Probably the customer will return the product. So we got the return, and the repair, and the work, and all those incur costs. And also probably the company needed to compensate the customer for the customer's inconvenience, or there are some, you know, other costs, opportunity costs involved in this process. In addition to the short-term costs, there are some long-term costs as well. For instance, as customer's perception deteriorates, in other words when the customer discovers some defect in, in the product then the customer's perception about the quality of the product, or even the company itself, the perception about the company goes down. So the customer's, you know, perception goes down, that means that the company's reputation goes down, and therefore customer's loyalty goes down, and that would eventually have a very negative impact on future sales. So this is very serious problem. This is very serious problem. There is another long-term ramification here. As the work increases, disruption inside the production system increases. And then process variability increases and that causes lots of problems in, in the production process. One of those problem is quality deterioration. Quality becomes worse, in other words the defects will increase. So this is kind of a vicious cycle. In order to prevent, in order to prevent these two different types of quality failure costs, the company must make some effort. Might do internal efforts. They try to minimize. They try to eliminate both internal quality failure and external quality failure. What are the costs? The cost is prevention cost, operation cost, and the, there are some activity cost as well. What kind of activity? Process, in quality, improvement activity. And therefore we can see that there are, you know, costs that occur internally and there are some costs that occurs externally. Which one is more serious? People might have a different idea, but in general we'll just say that the cost curve will look like this. In other words, let's say this is point of purchase. And, internal or inside the company, external or outside the company. The costs due to quality failures, plus some quality improvement to costs, right? We can add these two together and in general we believe that, the internal cost is up that much, but if the product, the defect occurs outside the company, the cost can be significant. And think about this recall, recalls in the automobile industry. If the car maker discover the defect of their cars before they actually sell the cost in the market, then probably the cost is not that great. But once you sell the car to the customer, and your car, your car's defect is discovered by the customer, then the cost is huge because it's not just a tangible cost only. We talked about some future, future sales. Future opportunistic, opportunist, opportunity costs as well, right? Opportunity costs as well. So the costs can skyrocket, and that sig, signifies the, you know, the, the company's initiative to spend more time and spend more resources to identify quality problems before, before their products go outside the company. That's very important. The company must try very hard so that they can avoid any extensive, any extraordinary external costs, external costs due to quality failure. [BLANK_AUDIO]