What is 3M(Muda,Mura,Muri) Model in lean manufacturing

What is 3M(Muda,Mura,Muri) Model in lean manufacturing

In lean manufacturing, the 3M Model refers to Muda, Mura, and Muri, which are three Japanese terms used to categorize and eliminate waste within a production process. Let’s explore each of these concepts with examples:

  1. Muda (Waste):
    • Overproduction: Producing more than what is required by the customer or ahead of demand, leading to excess inventory. For example, manufacturing products in large batches without considering actual customer demand.
    • Waiting: Idle time spent by workers or equipment due to delays in the production process. For example, waiting for materials or instructions to proceed with the next step in manufacturing.
    • Transportation: Unnecessary movement of materials or products between workstations, storage areas, or facilities. For example, excessive handling or transporting of components between different production stages.
    • Over-processing: Performing more work than necessary to meet customer requirements, leading to increased costs and complexity. For example, using higher-grade materials or precision machining when simpler methods would suffice.
    • Inventory: Excess inventory beyond what is required for immediate production or customer demand, tying up capital and storage space. For example, maintaining large stockpiles of finished goods that may become obsolete or deteriorate over time.
    • Motion: Unnecessary movement or motion by workers or equipment that does not contribute to value-added activities. For example, excessive walking or reaching to access tools or components.
  2. Mura (Unevenness):
    • Fluctuating Demand: Variability in customer demand or order patterns, leading to uneven production schedules and resource utilization. For example, experiencing spikes or lulls in customer orders that disrupt production flow.
    • Uneven Workload: Imbalance in workloads between different workstations or production processes, causing bottlenecks or underutilization of resources. For example, some workstations may be overburdened while others remain idle.
    • Unstable Processes: Inconsistencies or disruptions in production processes, resulting in quality issues, rework, or delays. For example, variations in machine performance or material quality affecting product consistency.
  3. Muri (Overburden):
    • Excessive Labor: Overworking employees beyond their capacity, leading to fatigue, errors, and reduced productivity. For example, expecting workers to meet unrealistic production targets without adequate breaks or support.
    • Equipment Strain: Subjecting machinery or equipment to excessive stress or usage, increasing the risk of breakdowns or maintenance issues. For example, running machines at maximum capacity for prolonged periods without proper maintenance or downtime.
    • Inefficient Layout: Poorly designed workspaces or layouts that create unnecessary strain on workers or equipment. For example, placing frequently used tools or materials too far from workstations, requiring excessive reaching or movement.

By identifying and addressing these forms of waste, unevenness, and overburden, lean manufacturing aims to streamline processes, improve efficiency, reduce costs, and enhance overall productivity and quality.


About user

Milind patel is an experienced practitioner and thought leader in the field of Business Process Management (CI) and 0.4 lean application. He co-founded Pro lean academy, a consulting company focusing on performance improvements and appropriate digitalization application in manufacturing process