Operations Management: Processes and Supply Chains, 12th Edition

Process Capability

Statistical process control techniques help managers achieve and maintain a process distribution that does not change in terms of its mean and variance. The control limits on the control charts signal when the mean or variability of the process changes. However, a process that is in statistical control may not be producing services or products according to their design specifications, because the control limits are based on the mean and variability of the sampling distribution, not the design specifications. Process capability refers to the ability of the process to meet the design specifications for a service or product. Design specifications often are expressed as a nominal value, or target, and a tolerance, or allowance ...