Literally translated, muda means “futility; uselessness; wastefulness,” though more broadly it refers to the seven common types of waste seen in business:
- Defects in the end product
- Time lost due to waiting for processes
- Non-essential movement
- Excess material inventory
- Excessive production
- Redundant processes
- Unnecessary transport or handling of materials or products
First recognized by Toyota Production System architect Taiichi Ohno (who also developed the kanban system), these forms of waste include anything beyond that which is strictly necessary to deliver a quality product to a customer as quickly as possible. If two bolts are required to assemble a widget, a third bolt off to the side of the workspace is waste. If a task calls for an employee to walk forward three steps to retrieve supplies, taking a fourth step would be waste.
Of course, these examples are both deliberately minor, to illustrate that lean manufacturing methods strive to eliminate all waste, no matter how inconsequential it may seem.