8 Waste of Lean Manufacturing
What is waste in Lean Manufacturing?
A core principle in lean methodology is the removal of waste within an operation. And in any business, one of the heaviest drains on profitability is waste. Lean waste can come in the form of time, material, and labor. But it may also be related to the utilization of skill-sets as well as poor planning. In lean manufacturing, waste is any expense or effort that is expended but which does not transform raw materials into an item the customer is willing to pay for.
Today, the Lean Manufacturing model recognizes 8 types of waste within an operation
1. Transport.
Transport waste is defined as any material movement that doesn’t directly support immediate production. An improper facility layout, poor production planning, poor scheduling can generate transport waste. Another example is poor workplace organization, which results, in unnecessary additional material transport.
Common types of Transportation Waste:
- Poor layouts – large distance between operations
- Long material handling systems
- Large Batch sizes
- Multiple storage facilities
- Poorly design production systems
How to spot it: Items being moved more than needed, often criss-crossing paths and hindering other movement in the facility.
Consequences: Longer lead times, increased transportation costs.
Possible solution: Reorganize workspaces or processes to reduce transport and optimize flow.
2. Inventory.
Inventory waste refers to any supply in excess of process requirements necessary to produce goods or services in a Just-in-Time manner. Causes of inventory waste include inaccurate forecasting systems, inefficient processes or suppliers, long changeover times, unbalanced production processes, or poor inventory management and tracking.
Common causes of Inventory Waste include:
- Overproduction of goods
- Delays in production or ‘waste of waiting’
- Inventory defects
- Excessive transportation
How to spot it: Examine inventory turnover data, physically review inventory.
Consequences: Higher costs for inventory storage space, management and maintenance; possible spoilage and other losses.
Possible solution: Review your inventory management.
3. Motion.
Motion waste is defined as any movement of people that doesn’t contribute added value to the product. Examples include moving equipment, reaching or bending, or gathering tools more than necessary, as well as unnecessarily complicated procedures. Motion waste is often caused by ineffective plant layouts, lack of visual controls, poor process documentation, or poor workplace organization.
Common causes of Motion Waste include:
- Poor workstation layout
- Poor production planning
- Poor process design
- Shared equipment and machines
- Siloed operations
- Lack of production standards
How to spot it: Employees spend excess time getting, moving or searching for tools, material or information. Excess injuries, errors, accidents and production delays.
Consequences: Longer lead times, higher production costs, lost time to injuries, lower production quality.
Possible solution: Improve workspace layout or production processes.
4. Waiting.
The waiting waste refers to as any idle time that occurs when codependent events aren’t fully synchronized. Examples of this waste include idle operators waiting for equipment, production bottlenecks, production waiting for operators, and unplanned equipment downtime. Waiting can be caused by inconsistent work methods, lack of proper equipment or materials, long setup times, low man/machine effectiveness, poor equipment maintenance, or skills monopolies.
Common causes of Waiting include:
- Unplanned downtime or Idle equipment
- Long or delayed set-up times
- Poor process communication
- Lack of process control
- Producing to a forecast
- Idle equipment
How to spot it: Employees are waiting for instructions, tools or material to complete tasks. Machines aren’t used to full capacity or at all.
Consequences: Costs resulting from lower productivity of employees or machines; opportunity costs are incurred due to underutilized production potential.
Possible solution: Improve communication with better work instructions and better capacity planning.
5. Overproduction.
Overproduction is defined as producing more than is needed, faster than needed, or before it’s needed. This form of waste is most commonly seen in a "push system" supply chain. Automation in the wrong places, lack of communication, local optimization, low uptimes, poor planning, and a just-in-case reward system can cause overproduction waste.
Common causes of Overproduction include:
- Unreliable process
- Unstable production schedules
- Inaccurate forecast and demand information
- Customer needs are not clear
- Poor automation
- Long or delayed set-up times
How to spot it: Accumulation of material or work in progress found near workstations.
Consequences: Higher costs for storage and labour to move and manage material; hindrance to workspace flow, clutter.
Possible solution: Proper planning of production to meet your customer demand.
6. Over-processing.
Over-processing refers to any redundant effort in production or communication that does not add value to a product or service. Over-processing waste includes endless product or process refinement, excessive information, process bottlenecks, redundant reviews and approvals, and unclear customer specifications. It is caused by decision-making at inappropriate levels, inefficient policies and procedures, lack of customer input concerning requirements, poor configuration control, and spurious quality standards.
Examples of Over-processing include:
- Poor communication
- Not understanding your customers’ needs
- Human error
- Slow approval process or excessive reporting
How to spot it: Products are overprocessed (i.e. made to higher specifications than customers need). Excess scrap material accumulates at workstations.
Consequences: Higher production and material costs.
Possible solution: Establish production standards.
7. Defects.
Defect waste is defined as the loss of value do to the scrap, repair, or rework of a product that deviates from specifications. Excessive variation in production processes, high inventory levels, inadequate tools or equipment, incompatible processes, insufficient training, or transport damage due to poor layouts and unnecessary handling can all lead to quality defect waste.
Specific Defect causes include:
- Poor quality control at the production level
- Poor machine repair
- Lack of proper documentation
- Lack of process standards
- Not understanding your customers’ needs
- Inaccurate inventory levels
How to spot it: Employees use incorrect processes; scrap material accumulates due to rework; high rates of defects, rework, returns and customer complaints.
Consequences: Lost sales; damaged brand; delivery delays; longer lead time; higher costs for labour, material and equipment to rework products.
Possible solution: Improve quality control, processes, standards, machine maintenance, training and work instructions.
8. Unutilized talent.
The waste of unutilized talent refers to underutilizing or engaging employees in a process. This could take the form of employees performing unnecessary work when their talent could be utilized in activities that add greater value, or not utilizing employees’ critical thinking abilities and feedback in processes. Unutilized talent also includes allowing employees to work in silos, which prevents them from sharing their knowledge.
Examples of Non-Utilized Talent:
- Poor communication
- Failure to involve people in workplace design and development
- Lack of or inappropriate policies
- Incomplete measures
- Poor management
- Lack of team training
How to spot it: Compare skillsets and assigned responsibilities; check performance evaluations for issues.
Consequences: Employees not performing to expectations, poor engagement, opportunity cost of underused skills.
Possible solution: Review employee responsibilities to better use talent; consider training to ensure employees can perform to the best of their abilities.
