Time when a person or process is idle because one or more inputs or resources is not ready. Waiting is one of the most common of the 7 types of waste. Waste is often hidden because processes are designed to keep people busy, which can result in overproduction and other waste.

Warusa Kagen

A Japanese phrase meaning “condition of badness". Used to express that before improvement can happen we need to recognize what is bad about the process or the current situation.


Activity that adds cost but not value to a product, service or experience.

Waste Walk

A structured activity to visit the workplace, observe and identify the seven (or eight) types of waste within the workplace.

Water Beetle

Water Spider

The water spider is a skilled and well-trained person who follows a routine of longer-cycle and occasional tasks to keep the main production line running smoothly. A water spider makes the rounds supplying materials, assisting with changeovers, providing tools and materials, and any additional help needed to maintain Standard Work and keep the flow going. The water spider knows all processes thoroughly enough to step in if needed. Performing the water spider role is often a gateway for supervision and management positions. The name comes from the whirligig beetle that swims about quickly in the water.

Water Strider

Waterfall Charts

A waterfall chart is a type of data visualization used to represent a sequence of incremental changes to an initial value. It helps in understanding how an initial value is affected by a series of intermediate positive or negative values. The chart is typically used in financial analysis to track the cumulative effect of sequentially introduced positive or negative values. Each bar in the chart shows how an initial value is increased or decreased by subsequent data points, leading to a final value. Waterfall charts are useful for understanding the progression of a value, such as revenue or profit over time, and for identifying which factors contribute to a decrease or increase in the final figure. They are often used in business and finance for budget analysis, profit and loss analysis, and performance reporting.


Abbreviation for "What's In It For Me?" which is a question on people's mind that must be answered when trying to make sustainable improvements.

Withdrawal Kanban

A signal that specifies the type and quantity of product that the downstream process may withdraw.

Work Cell

An arrangement of people, machines, materials and methods in sequential order so that parts can be processed one at a time with minimal inventory, transportation or delay.

Work Element

A single task that can't be subdivided further.

Work Instructions

The specific and detailed information on how to perform a task. Work instructions document the step-by-step activities, methods used to do the tasks, and specify various inputs and requirements such as tools, material type and quantity, safety reminders, and images of correct and incorrect application.

Work Sampling

A work measurement technique where observations are collected at discrete time intervals, either periodic or random.

Work Sequence

The defined steps and activities that must be performed in specific order for work to be completed. One of the three elements of standard work.


Any inventory between raw materials and finished goods to which some value or cost has been added.

Workload Balancing

The distribution of work tasks across people, processes, or equipment so that each has the same workload in terms of time, enabling even and smooth flow.


An incomplete, unofficial, or temporary fix for a problem. Workarounds address symptoms of a problem but not the causes. Although workarounds are intended to be temporary, they are often left in place longer than planned, and may not stand up under increased demand or burden on the process.

Work Sequence

One of the three elements of standard work, is the defined steps and activities that need to be performed in order for the work to be completed.

Workstation Design

The design, customization, modification, or construction of a specific work area so that it contains work surfaces, fixtures, tools, and materials, and other resources needed to perform a job successfully according to Lean principles.