muda (Waste) = Elements that add time, effort, cost but no value.
muda is found when resources are expended yet no real value is added or offered to the customers. So Lean focuses on creation of value for the end customers. Whatever activity is done within a process can be termed as value adding (VA) or non-value adding (NVA), so Lean examines each activity within a process and categorizes it as either VA or NVA.
If an activity consumes time or capital but does not add value it is NVA activity and it must be identified, reduced and eliminated as the customers are typically not willing to pay for this. In many organizations more than 90% of the activities and time in processes do not add value. The key is to eliminate these eight wastes. By eliminating these eight wastes you will increase your VA abilities which will ultimately increase profitability.
The acronym for the eight wastes is DOWNTIME. Downtime stands for:
Non-value added processing
Manufacturing’s Deadly Sins
- Inventory Waste
- Waiting Time
- Transportation Waste
- Processing Waste
- Waste of Motion
- Product Defects
- Underutilized People
- If you make more product than is required by the next process, make it earlier than is required by the next process, or make product faster than is required by the next process, you overproduce.
- Just-in-case logic & misuse of automation
- Long process set-up
- Unlevel scheduling & unbalanced work load
- Over engineered
- Redundant inspections.
- Any supply in excess of a one-piece flow through your manufacturing process
- Causes of excess inventory
- Protects the company from inefficiencies and unexpected problems.
- Product complexity
- Unbalanced workload, unleveled scheduling
- Poor Market forecast
- Unreliable shipments by suppliers
- Misunderstood communications
- Reward system.
- Idle time created when waiting for…?
- Causes of Waiting Waste
- Unbalanced work load & un-level scheduling
- Unplanned maintenance
- Long process set-up times
- Misuses of automation
- Upstream quality problem.
Waste of Transportation
- Transporting parts and materials around the plant without adding value
- Poor plant layout
- Poor understanding of the process flow for production
- Large batch sizes, long Lead Times, and large storage areas.
- Effort that adds no value to the product or service from the customers’ viewpoint
- Product changes without process changes
- Just-in-case logic
- True customer requirements undefined
- Over processing to accommodate downtime
- Lack of communications & redundant approvals
- Extra copies/excessive information.
- Any movement of people or machines without adding value
- Poor people/machine effectiveness
- Inconsistent work methods
- Unfavorable facility or cell layout
- Poor workplace organization and housekeeping
- Extra “busy” movements while waiting.
- Inspection and repair of material in inventory
- Weak process control
- Poor product & process design
- Unbalanced inventory level
- Deficient planned maintenance
- Inadequate education/training/work instructions
- Misunderstood Customer needs.
- Not using people’s (mental, creative, physical, skill) abilities.
- Management by fear and directive, politics
- Poor hiring practices
- Low or no investment in training
- Low pay, high turn over strategy
Things to remember
muda is really a symptom rather than a root cause of the problem
muda points to problems within the system (At both process & value stream levels)