The acceptable quality level sets a minimum standard for quality performance in batch manufacturing, with a predetermined number of defects allowed. Similar products should be grouped together, and a reject rate determined through comprehensive testing. Control charts are useful for measuring and improving quality levels.
For manufactured goods, the acceptable quality level is used to determine overall consistency based on predetermined performance standards set using a statistical model. In a batch manufacturing scenario, the acceptable quality level sets the standard for a minimum level of quality performance. It helps ensure that the average batch of product manufactured meets or exceeds an established set of requirements.
One way to think of an acceptable quality level is as the absolute minimum quality performance that will allow a batch to pass without a thorough inspection. Each batch of product can have an allowed number of defects. If the quantity of defects allowed is set too low, it can result in the time and expense required to inspect each item produced by the lot.
To measure an acceptable level of quality, similar products should be grouped together. In other words, lots shouldn’t include unrelated products that might use different processes, such as shoes and bicycles. Production specifications should be the same for each batch.
A reject rate must be determined to measure an acceptable level of quality. For example, for an average batch of 30 shoes, a scrap rate of two might be established. This rate is recorded by randomly pulling products from each batch off the production line within specified time increments. The randomly drawn product undergoes comprehensive testing to ensure that the quality meets predetermined standards.
It is recommended to evaluate batch samples during the actual production process to avoid costly inspections. Waiting until the end of the manufacturing process to find defects may mean that each item in the batch needs to be examined to eliminate those deemed unacceptable. A sample size should be determined; this refers to the number of products that will be randomly drawn during production.
The predetermined requirements concern the manufacturing process, as well as visible defects in the finished product. A food manufacturer may want to ensure that a certain temperature has been used during the time the product has been in the oven or that the product has been cut to maintain a specific level of thickness. You may need to comply with industry and safety standards, such as with medical syringes. These types of products will most likely require thorough visual and functional testing to ensure reliable performance.
Control charts show the standards that each batch must pass and are a useful tool for measuring acceptable quality levels. Higher quality can be achieved with tighter control factors. When measuring quality levels, control charts provide a reference to each stage of the process the product has to go through. They help to identify possible problems in the production process that could cause poor quality levels.
Protect your devices with Threat Protection by NordVPN
