Eight Wastes of Lean
Praneet H. Surti, PMP?
Manager - Business Quality | Operational Excellence | PMP? | Lean Expert | Six Sigma - Black Belt | TQM | TPM | Lead Auditor ISO 9001 | B.E Mechanical | Classic Rock Enthusiast??????| Management Consultant
Eliminating wasteful activities is one of the most important prerequisites for building a successful company. This concept is an integral part of Lean Thinking and it helps increase productivity.
Lean manufacturing is a methodology derived from the Toyota Production System that focuses on minimizing waste within manufacturing systems while simultaneously maximizing productivity. Lean aims at eliminating the three types of deviations that show an inefficient allocation of resources. The three types are: ? Muda (無駄, Waste) ? Mura (æ–‘, Unevenness) ? & Muri (ç„¡ç†, Overburden)
Waste [Muda]
Waste is any action or step in a process that adds cost but negates the value. Muda takes into account the wastes and aims to integrate each step of production into a holistic, efficient process that reduces costs and improves overall revenue. The original seven wastes (Muda) was developed by Taiichi Ohno, the Chief Engineer at Toyota, as part of the Toyota Production System (TPS). The seven wastes are Transportation, Inventory, Motion, Waiting, Overproduction, Over-processing and Defects. They are often referred to by the acronym ‘TIMWOOD’. The 8th waste of non-utilized talent or ‘Skills’ of workers was later introduced in the 1990s when the Toyota Production System was adopted in the western world. As a result, the 8 wastes are commonly referred to as ‘TIMWOODS’
1. Transport
Transport refers to the movement of people, tools, inventory, equipment, or products further than necessary in between processes.
It refers: A cost incursion, Adds no value to the product, Wastes time and energy § Can end up damaging the products themselves. Excess transportation may be caused by: Poor layouts, Large distance between operations, Lengthy, or complex material handling systems. Working to a faster rate than customer demand, Multiple storage locations
Optimal Practices
Utilizing most efficient routes (most obvious route may not be most efficient)
Staging processes as close together as possible
Optimizing material handling systems and consolidate storage areas
Avoiding lengthy or complex material-handling systems Transport
2. Inventory
Inventory waste is stock in excess of the requirements necessary to produce goods or services ‘Just In Time’ Excess inventory increases lead times, consumes productive floor space, delays the identification of problems, and inhibits communication.
Excess inventory can be caused by: Over-purchasing, Inventory Build-up between Processes, Large Batch Sizes. Stagnant Materials
Optimal Practices
Purchasing raw materials only when needed and in the quantity
Reducing buffers between production steps
Adjusting the production process to create a smooth flow of labor
Observing the First-In-First-Out principle regarding stagnant materials
Creating a queue system to prevent overproduction.
Use Just-in-Time (JIT) inventory techniques Inventory
3. Motion
Any unnecessary movement of people, equipment, or machinery which includes walking, lifting, reaching, bending, stretching, and moving. It can include repetitive movements that do not add value to the customer, reaching for materials, walking to get a tool or materials, and readjusting a component after it has been installed. Wasteful motion is caused by: Poor Workstation Layout, Poor Workplace Organization, Large Batch Sizes, Reorientation Of Materials
Optimal Practices
Improving workstation layouts to prevent excessive walking, bending, or reaching Arranging methods to allow parts to transfer smoothly from one hand to the other Redesigning the workplace layout to allow for less reorientation of materials
Placing equipment near the production location
Putting materials at an ergonomic position to reduce stretching and straining.
4. Waiting
Waiting involves any idle time produced when two interdependent processes aren't completely synchronized. This can be caused by machines, products, people, and information that forces operators to wait or work inefficiently. A lot of our time waiting for various reasons that may include:
Previous operations running over their expected time
Deliveries failing to arrive
Unreliable people and machines
Poor Man/Machine coordination
Need for batch, instead of a single product, completion
The time required to rework a product
Optimal Practices
Designing processes to ensure continuous flow or single piece flow
Synchronizing processes (machine & human) as best as possible
Leveling out the workload by using Standardized Work Instructions
Increasing reliability of processes
Reducing downtime by improving efficiency
Developing flexible multi-skilled workers who can quickly adjust in the work demands
5. Overproduction
Overproduction is to manufacture an item before it is actually required. As it is tempting to produce as many products as possible when there is idle worker or equipment time. Overproduction costs are high to a manufacturing plant as it not only prohibits the smooth flow of materials but actually degrades quality and productivity. This creates excessive lead times, results in high storage costs, and makes it difficult to detect defects. Overproduction works in two forms: Producing something before it is needed § Producing too much of a product, resulting in work-in-progress and surplus stock
Optimal Practices
Balancing Supply and Demand
Producing per actual demand rather than forecasted sales
Adopting Just-in-Time (JIT) manufacturing philosophy
Creating more reliable processes
6. Over Processing
Over-processing refers to doing more work, adding more components, or having more steps in a product or service than what is required by the customer. Which includes: Using higher precision equipment than necessary
Using components with capacities beyond what is required
Running more analysis than needed
Over-engineering a solution
Adjusting a component after it has already been installed
Having more functionalities in a product than needed
Generating more detailed reports than needed
Having unnecessary steps in the SOPs
The duplicate entry of data in multiple documents
Optimal Practices
Clarifying Customer’s standards and expectations ahead of time
Producing to the level of quality and expectation that the customer desires, and make only the quantities needed
Only performing the processes necessary to meet these standards and expectations Using appropriate processes (Avoid overly complex machinery or processes if possible) §
Standardizing best techniques for workers to follow
Setting clear specifications and quality acceptance
7. Defect
Defects occur due to variation in the standard operating process & leads to the manufacturing of product which is not fit for use, resulting in either Reworking or Scrapping the product. Both results are wasteful as they add additional costs to the operations includes Quarantining Inventory, Re-inspecting, Rescheduling & Capacity Loss, without delivering any value to the customer. Defects are caused by: Inadequate Training, Skills Shortage, Incapable Processes, Incapable Suppliers, Operator Error, Excessive Stock & Transportation
Optimal Practices:
Developing a world-class quality assurance program
Focusing on preventing defects rather than resolving problems post-production § Seeking for the most frequent defect and focus on it.
Designing a process to detect abnormalities and do not pass any defective items along the production process.
Standardizing work to ensure a consistent manufacturing process that is defect-free. Routine Training, Capable Suppliers, Reduce Excess Stock, etc.
Implementing a Poka-Yoke ("Mistake-Proofing") system to reduce defects
8. Unutilized Talent
This waste occurs when organizations separate the role of management from employees. In some organizations, management’s responsibility is planning, organizing, controlling, and innovating the production process. The employee’s role is to simply follow orders and execute the work as planned. By not engaging the frontline worker’s knowledge and expertise, it is difficult to improve processes. As people doing the work are the ones who are most capable of identifying problems and developing solutions for them. non-utilized talent includes: Insufficient Training, Poor Incentives, Not asking for employee feedback, Placing employees in positions below their skills and qualifications
Optimal Practices
Appropriate TNI & Sufficient Training to Employees
Talent Based Incentives
Routine employee feedback
Placing employees in positions as per their Talent, Skills, & Qualifications
The first step to reducing waste is recognizing its existence & having an effective process for identifying them Value Stream Mapping (VSM) is a Lean management method for analyzing the current state and designing a future state. It shows the flow of information and material as they occur. It effectively maps out the processes involved, displaying the relationship between production processes in a visual manner separating value-added and non-value-added activities
Using the VSM and start with the end customer in mind
Working backward from the end customer to the start of the production processes
Documenting instances of the 8 wastes in the processes and develop a plan for eliminating or reducing them
Continuing challenging the team to find more wastes and continuously improve your processes
Engaging with the front-line workers and elicit their ideas for improvement
As the team begins reducing efficiency they will gain more confidence in their problem-solving capabilities and over time reducing waste becomes a part of their daily routine Identifying and Eliminating the Wastes
References: Leanmanufacturingtools.org l leanop.com l en.wikipedia.org l leanmanufacturingtools.org l www.kainexus.com
Management Consultant (HR - Policy & Talent Strategy) RDD BRLPS Govt. of Bihar ll Project Concern International ll PwC ll NACHRCOI ll Aarti Industries Ltd ll Air India Sats ll Totem International Ltd ll Alph Eta Rho
5 å¹´Awesome write up on 8 waste of Lean Management. And very researched article though. Well done Praneet Surti. Best wishes ?? ??