W

Waste: Any activity that consumes resources and produces no added value to the product or service a customer receives. Also known as muda.

Weighed voting: A way to prioritize a list of issues, ideas or attributes by assigning points to each item based on its relative importance.

Wilcoxon Mann-Whitney test: Used to test the null hypothesis that two populations have identical distribution functions against the alternative hypothesis that the two distribution functions differ only with respect to location (median), if at all. It does not require the assumption that the differences between the two samples are normally distributed. In many applications, it is used in place of the two sample t-test when the normality assumption is questionable. This test can also be applied when the observations in a sample of data are ranks, that is, ordinal data rather than direct measurements.

Work in process: Items between machines or equipment waiting to be processed.

Work team: See “natural team.”

Working sequence: One of three elements of standard work; refers to the sequence of operations in a single process that leads a floor worker to most efficiently produce quality goods.

World-class quality: A term used to indicate a standard of excellence: best of the best.