8 Wastes of lean
Taiichi Ohno — a Japanese Industrial Engineer, was known as the father of the Toyota Production System. While searching for better ways to optimize resources, Ohno identified 7 lean wastes (Muda in Japanese) in manufacturing processes (the 8th waste was added in the 90s).
The 8 wastes are known as TIMWOODS —
The 8 waste methodology was originally developed for the automobile sector. But as time passed, multiple industries across the vertices started utilizing it to add value to the business processes.
We will examine each of these wastes in detail below:
The waste of transportation is the moment of people, tools, inventory, equipment, or products in access. It’s the excess moment of resources being utilized for the customers first-hand. In any business process, there happens to be the shortest transport distance. Having to move work in process from department to department when simpler production compositions are available, the process is considered to be a waste.
Sometimes it gets tough to think of inventory in excess as waste. It’s because inventory is considered an asset. But inventory in excess is a waste for sure! It can create problems such as greater lead times in the production process, inefficient allocation of resources, defects or damage to materials and problems hidden in the inventory that take longer to surface. Excessiveness can be caused by over-purchasing of raw materials and supplies, overproducing of work in process by having long queues, or producing more product than the customer’s requirement.
This type of waste is the unnecessary movement of people, machinery, or equipment. This includes walking, lifting, reaching, bending, stretching, and moving. To reduce this kind of waste, tasks that require excessive motion should be redesigned to enhance the work of personnel and increase the health and safety levels.
Waiting time is often caused by halts and jump points in the production stations and can result in excess inventory and overproduction. Waiting waste can also be generated by upstream processes that are unpredictable due to disruptions or quality issues.
The waste of waiting for includes:
1) People waiting on material or equipment
2) Idle equipment
Countermeasures to reduce Waiting waste include:
- Designing processes to ensure continuous flow or single piece flow
- Levelling the workload by using standardized instructions
- Developing flexible multi-skilled workers according to work demands
Production of waste occurs when it is made in excess. It happens when manufacturing a product before its demand. It may be tempting to produce products early hand when there’s an idle workforce. However, it’s more sensible to do the ‘Just in Case’ way of working that will lead to a smooth workflow and lower storage costs.
6) Over Processing
Over-processing waste refers to doing and adding features or steps in excess. Over-processing waste includes:
- Tolerances that are tighter than function requires
- Components with higher -capacities for an additional “margin for safety”.
- Having more functions than what the user asked for.
There are three countermeasures for overproduction.
- Using a Takt Time ensures that the rate of manufacturing between stations is even.
- Reducing setup times enables manufacturing small batches or single-piece flow.
- Using a pull or Kanban system can control the amount of work in progress
Defects take place when a product is not fit for use. This results in either design re-work or scrapping of the product. Both processes are waste as they add additional cost to the operations without really delivering any value.
Defects can lead to delivery delays and sometimes may hamper a brand’s reputation in the market. In order to battle defects one can utilize:
- Pareto charts to identify errors
- Poka Yoka process to stop and detect defects
- Jikoda to eliminate the chances of defects.
This kind of waste is expressed as the waste of unused human talent and ingenuity. This waste occurs when an organization separates the role of management from employees.
In some organizations, management’s responsibility is planning, organizing, controlling, and innovating the production process.
An employee’s role is to follow the orders and execute the work as tasked. By not engaging the workers, it becomes difficult to improve processes.
Identifying and Reducing the Waste
To identify the waste, one can use Value Stream Mapping (VSM) and start with the end customer. The manner of working from the back of the end customer perspective to the production process must be followed. Even documenting the wastes can be kept in check. Continually challenge your team to identify more wastes which will improve processes. Engage in the frontline alongside the core workers to bring new ideas in front. By focusing on these lean manufacturing wastes, you will be better equipped to pursue growth in stronger operations.