W. Edwards Deming

A renowned statistician and quality management pioneer whose principles and teachings (such as the 14 Points for Management and the System of Profound Knowledge) greatly influenced modern quality improvement and Lean manufacturing.
See also: Deming Cycle (PDCA), Total Quality Management (TQM)

Waiting

A form of waste in processes where people, materials, or information are idle, often due to bottlenecks or inefficient workflows.
See also: Waste, Lean Manufacturing

Waste

Any activity or resource in a process that does not add value from the customer’s perspective. Common types include defects, overproduction, waiting, non-utilized talent, transportation, inventory, motion, and extra processing (the 8 wastes of Lean).
See also: Lean Manufacturing, Value Added

Wilcoxon Mann-Whitney test

A nonparametric statistical test used to compare differences between two independent groups when the data are not normally distributed.
See also: Nonparametric Test, Hypothesis Testing

Wilcoxon signed-rank test

A nonparametric statistical test used to compare two related samples or repeated measurements on a single sample to assess whether their population mean ranks differ.
See also: Nonparametric Test, Paired Data

Work cell

A physical arrangement of resources and equipment in a manufacturing or service environment designed to improve flow and efficiency for a specific set of tasks or products.
See also: Cellular Manufacturing, Lean Manufacturing

Work instruction

A detailed, step-by-step description of how to perform a specific task or process, used to ensure consistency and quality.
See also: Standard Operating Procedure (SOP), Process Documentation

Work in process (WIP)

Items or materials that are in various stages of completion within a production process but are not yet finished goods.
See also: Inventory, Throughput

Work breakdown structure (WBS)

A hierarchical decomposition of a project into smaller, more manageable components, tasks, or deliverables.
See also: Project Management, Gantt Chart

World-class quality

A level of quality that meets or exceeds the highest global standards, often characterized by near-zero defects, high customer satisfaction, and continuous improvement.
See also: Benchmarking, Total Quality Management (TQM)