Lean and Quality Management Glossary: Key Terms and Definitions for Operational Excellence

Welcome to our glossary! Here, you will find a collection of definitions and explanations of key terms related to Lean, quality management, operational excellence, and other related business concepts. Our glossary is intended to help you understand these terms and their significance in the business world, whether you are a seasoned professional or just starting to learn about these concepts. We strive to provide clear, concise, and accurate definitions that are easy to understand. Our goal is to create a resource that you can use as a reference guide whenever you encounter unfamiliar terms or concepts. We hope that our glossary will be a useful tool to enhance your knowledge and understanding of these important business topics.

Baka yoke

Baka yoke (idiot proofing) is a Lean and quality tool used in product design to prevent defects and errors by implementing mistake-proofing mechanisms and processes. The goal of Baka yoke is to ensure that the product or process is designed in a way that it cannot be used or assembled incorrectly, leading to improved quality and reduced costs associated with defects and errors. Note the updated and preferred term to use is Poka yoke (mistake proofing).

Black belt

In Six Sigma, a Black Belt is a highly skilled professional who has completed an advanced level of training in Six Sigma methodologies and tools. Black Belts are responsible for leading and implementing improvement projects within an organisation, typically working full-time on Six Sigma projects and leading Green Belts and other team members in the project. Black Belts are knowledgeable in statistical analysis and problem-solving techniques and are expected to achieve significant improvements in process performance and quality through their projects. If they are not working full time on Six Sigma projects they will utilise their skills to enhance their roles and organisations.

BOM (Bill of materials)

BOM (Bill of Materials) is a comprehensive list of all the materials, components, and assemblies required to manufacture a product.


A bottleneck, in Lean, is a process step that limits the overall capacity of a system due to its slower pace or resource constraints, causing a delay in the production or delivery of products/services.

Bowling chart

A Bowling Chart is a visual management tool used in Lean manufacturing to track progress towards achieving production targets, by measuring actual production output against the planned target, and then using the chart to identify and address any deviations or issues.

BPMN (Business process model notation)

BPMN (Business Process Model and Notation) is a graphical modeling language used for representing business processes, workflows, and procedures in a standardised and easily understandable way. It provides a visual representation of the sequence of events, activities, and decisions involved in a business process and allows stakeholders to understand and improve the process more effectively.


In Lean, a buffer is a reserved capacity, material, or time used to protect a process or system from disruptions and uncertainties in demand, supply, or production.

Bullwhip effect

The bullwhip effect is a phenomenon in supply chain management where small changes in consumer demand lead to larger and more erratic fluctuations in demand further up the supply chain, resulting in inefficiencies, excess inventory, and increased costs.

Business process reengineering (BPR)

Business process reengineering (BPR) is the radical redesign of business processes with the goal of achieving significant improvements in performance measures such as cost, quality, service, and speed. BPR involves questioning existing processes and assumptions, and redesigning processes to take advantage of new technology, organisational structures, and management practices.

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