The 8 Types of Wastes in Lean Six Sigma

Lean thinking aims to remove wastes from work processes. Before diving into the 8 wastes, it is important to understand what waste is. Waste is any action or step in a process that does not add value to the customer. In other words, waste is any process that the customer does not want to pay for.

Following are eight types of wastes.

Defects

Defects occurs when the product is not fit for use. This typically results in either reworking or scrapping the product. Both results are wasteful as they add additional costs to the operations without delivering any value to the customer.

Overproduction

Overproduction occurs when manufacturing a product or an element of the product before it is being asked for or required. It may be tempting to produce as many products as possible when there is idle worker or equipment time. However, rather than producing products just when they are needed under the ‘Just In Time’ philosophy, the ‘Just In Case’ way of working leads a host of problems including preventing smooth flow of work, requiring more capital expenditure to fund the production process, and excessive lead-time. Additionally, over-producing a product also leads to an increase in likelihood that the product or quantities of products produced are beyond the customer’s requirements.

Waiting

The waste of waiting includes: 1) people waiting on material or equipment and 2) idle equipment. Waiting time is often caused by unevenness in the production stations and can result in excess inventory and overproduction.

In the office, waiting waste can include waiting for others to respond to an email, having files waiting for review, ineffective meetings, and waiting for the computer to load a program. In the manufacturing facility, waiting waste can include waiting for materials to arrive, waiting for the proper instructions to start manufacturing, and having equipment with insufficient capacity.

Skill/Unused human 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. This is due to the fact that the people doing the work are the ones who are most capable of identifying problems and developing solutions for them.

In the office, non-utilized talent could include insufficient training, poor incentives, not asking for employee feedback, and placing employees in positions below their skills and qualifications. In manufacturing, this waste can be seen when employees are poorly trained, employees not knowing how to effectively operate equipment, when employees are given the wrong tool for the job, and when employees are not challenged to come up with ideas to improve the work.

Transportation

Waste in transportation includes movement of people, tools, inventory, equipment, or products further than necessary. Excessive movement of materials can lead to product damage and defects. Additionally, excessive movement of people and equipment can lead to unnecessary work, greater wear and tear, and exhaustion.

In the office, workers who collaborate with each other often should be close together. In the factory, materials necessary for production should be easily accessible at the production location and double or triple handling of materials should be avoided.

Inventory

Often times it is difficult to think about excess inventory as waste. In accounting, inventory is seen as an asset and oftentimes suppliers give discount for bulk purchases. But having more inventory than necessary to sustain a steady flow of work can lead to problems including product defects or damage materials, greater lead time in the production process, an inefficient allocation of capital, and problems being hidden away in the inventory. Excess inventory can be caused by over-purchasing, overproducing work in process (WIP), or producing more products than the customer needs. Excess inventory prevents detecting production-related problems since defects have time to accumulate before it is discovered. As a result, more work will be needed to correct the defects.

In-office inventory waste could be files waiting to be worked on, customers waiting for service, unused records in a database, or obsolete files. Manufacturing inventory waste could include broken machines sitting around, more finished products than demanded, extra materials taking up work space, and finished products that cannot be sold.

Motion

The waste in motion includes any unnecessary movement of people, equipment, or machinery. This includes walking, lifting, reaching, bending, stretching, and moving. Tasks that require excessive motion should be redesigned to enhance the work of personnel and increase the health and safety levels.

In the office, wasted motion can include walking, reaching to get materials, searching for files, sifting through inventory to find what is needed, excess mouse clicks, and double entry of data. Manufacturing motion waste 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.

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. In manufacturing this could include using a 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, and having more functionalities in a product than needed. In the office, over-processing can include generating more detailed reports than needed, having unnecessary steps in the purchasing process, requiring unnecessary signatures on a document, double entry of data, requiring more forms than needed, and having an extra step in a workflow.

How to Reduce Waste Using Lean Six Sigma?

Once the waste has been identified using the TIMWOODS method of Lean Six Sigma, then organizations can begin working towards reducing or eliminating it.

Companies often use Value Stream Mapping (VSM), which is a Lean management method, to help them understand the existing state of their company waste and to help them design the future state of waste in the company.

VSM easily maps out the processes, shows the relationship between them, and segregates the activities that add value and the ones which do not add value in a visual manner. VSM should be used by keeping the customer in mind while starting and tracing it back to the production processes.

Some tips to reduce the TIMWOODS waste using Lean Six Sigma, once it has been identified, are:

Transportation – Reduce non-essential transportation in production by creating a U-shape production line or reducing the amount of work in progress. Companies can also create different flows between processes.

Inventory – Improving the forecasting methods in the company, buying materials only when needed in the required quantity, and reducing gaps in production.

Motion – Design workstation in a way that minimizes movement in an organized, ergonomic fashion to reduce the strain. 

Waiting – Improve communication and reduce waiting time so that companies can eliminate bottlenecks in their production process and have a continuous flow when they work.

Overproduction – Create a made-to-order philosophy in companies by scheduling and forecasting. Use a Takt Time, reduce set up time, and use a Kanban system or a pull system to monitor the work in progress.

Over-processing – Use Value Stream Mapping and analyze the value generated, starting from the customer and ending with the production house, to identify wasted effort.

Defects – Use DMAIC to find the root cause of the problem and eliminate them. Design a process that helps in detecting any defects during production itself and standardize all changes.

Skills – Use incentives for employees and create a reward system to keep them motivated and use their talent to its full potential.

Abdul Gafoor

MBA Logistics Management

www.digitalsupplychaintoday.com