Six Sigma Green Belt Certification Practice Exam

An operator being unable to work due to a broken machine is an example of which type of muda?

1. Transport

2. Processing

3. Waiting

4. Motion

The correct answer is: Waiting

The situation described, where an operator is unable to work because of a broken machine, exemplifies the concept of waiting muda. In Lean methodology, muda refers to any activity that does not add value to the product or service and represents waste. When a machine is not functioning, the operator cannot continue their work, leading to idle time where no value is being created. This absence of productive activity while waiting for repairs or resolution is classified as waiting muda. Understanding the types of muda is crucial in Lean practices, as it helps identify areas where efficiency can be improved. While transport muda relates to unnecessary movement of materials, processing muda pertains to inefficiencies in the actual workings of processes, and motion muda involves unnecessary movements by workers, the scenario presented specifically highlights the idle time experienced due to equipment failure, which is best characterized as waiting. This identification can ultimately lead to actions that reduce or eliminate such downtime, improving overall operational efficiency.