In acceptance sampling, it identifies the quality level required in order for lots to be considered to be good. See acceptance sampling.
Extracting a sample group from a large quantity of products or components of interest. Also known as a “lot,” and, based on the quality level of the sample group, the entire lot is either god or bad.
assignable cause variability
Variability in process outcomes that results from special causes that are not part of the inherent random fluctuation of the process and indicate that something in the process has changed.
A product or service characteristic that can be classified as either conforming or not conforming to specifications.
A process control chart used to monitor counts of nonconformities per unit.
A measure of process capability.
cause and effect diagram
A tool used to aid in the identification of root causes or quality problems.
A quality analysis tool used to tally occurrences of interest.
common cause variability
Variability in process outcomes that results from the inherent random fluctuation of the process.
In acceptance sampling, the probability of accepting a bad lot, designated as β.
In a process control chart, these are typically three standard deviations above and below the process mean.
customer relationship management (CRM)
Systems designed to improve relationships with customers and improve the business’s ability to identify valuable customers. They include call center management software, sales tracking, and customer service.
In moment-of-truth analysis, when an experience viewed by the customer is viewed as a detractor or as something that signifies a reduction in the quality of service.
In moment-of-truth analysis, these are experiences that make the customer feel good about the interaction and make the interaction better.
A bar graph that plots a measurement on the y axis and the frequency of the occurrence of the measurement on the x axis.
lot tolerance percent defective (LTPD)
In acceptance sampling, the level of quality in the lot that would be unacceptable to the customer. See acceptance sampling.
The identification of the critical instances when a customer judges service quality and determines the experience enhancers, standard expectations, and experience detractors.
operating characteristics (OC) curve
Used in the development of acceptance sampling plans, this is a graph that demonstrates how well the plan discriminates between good and bad quality by showing the probability of accepting a lot of LTPD quality (a bad lot) and the probability of rejecting a lot of AQL quality (a good lot).
A process control chart used to monitor the percent defective in a sample.
A process used to separate the relatively few important problems from the many unimportant ones.
A bar graph used to categorize data and help establish priorities.
The ability of a process to consistently meet customer expectations, demonstrated by the control limits being within the customer specifications.
In acceptance sampling, this is the probability of rejecting a good lot, indicated by α.
A process control chart used to monitor sample ranges.
Policies for how employees are to deal with quality failures so that customers will return.
Designing products and services so that they perform over a wide range of conditions.
A plot of a variable of interest on the y axis and time on the x axis.
A chart that seeks to identify relationships between variables by plotting one variable on the x axis and another on the y axis.
In moment-of-truth analysis, these are experiences that are expected and taken for granted by customers.
statistical process control
A preventive approach to managing quality by monitoring processes in a way that identifies potential problems before defects are even created.
statistical process control chart
A specific type of run chart used to plot measurements or test outcomes against time and distinguish between variability caused by random fluctuation and variability that has an assignable cause.
A process control chart that is used to monitor the sample means of variables that result from a process.