The 8 Wastes of Lean: What they Mean and Why they Matter!

By: Scott Roeder

It all started with Taiichi Ohno, he was a Japanese Industrial Engineer who was the father of the Toyota Production System.  In searching to optimize the use of resources, Ohno identified seven wastes (or Muda in Japanese) in manufacturing processes. An eighth waste was added in the 1990s as the Toyota Production System was adopted by manufacturers in the rest of the world as Lean Manufacturing. The eight wastes are represented by a mnemonic, TIMWOODS, which stands for Transportation, Inventory, Motion, Waiting, Overproduction, Over-Processing, Defects, and unused Skills. While the concept of the eight wastes was developed in automotive manufacturing and used widely in manufacturing for years, they can be applied to any process used to create value.  Let us review each of these wastes in detail and see how they may be addressed.

Waste of Overproduction

The first waste that we will examine is the one that is considered the worst waste, the waste of Overproduction.  It is making products in greater quantity or sooner than they are needed, leading to excess inventory, and tying up resources that cannot be transformed into cash.  Overproduction hides other problems within your processes, defects that are sorted out, movement and storage of inventory, delay of other products with waiting customers.  Overproduction can be spread into all areas of the process, causing resources to be tied up as raw materials, work in progress, products for rework and finished goods.  Any time product is created “just in case”, the waste of overproduction is present.

In an office environment, overproduction examples include making extra copies, redundant document storage (hard and electronic copies), reporting in greater detail than was asked for and distributing emails to a larger audience than required.

Tools to battle Overproduction waste:

• Calculate and institute Takt Time for processes
• Reducing setup times to enable one-piece flow
• Using a Kanban or pull system to control work in process

Waste of Inventory

The next waste that we will consider is the waste of Inventory. It is sometimes difficult to think of excess inventory as a waste.  In financial accounting, inventory is considered an asset and discounts are often given for making bulk purchases.  But excess inventory, more than is required for a steady flow of production, 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.  Excess inventory can be caused by over-purchasing of raw materials and supplies, overproducing work in process by having large batches and queues or, producing more product than the customer needs now.  You can see how the waste of Overproduction leads to the waste of Inventory.

In an office environment, excess inventory tends to take the shape of work in process or unused and obsolete files and records.  Whenever there are large queues of items to work on, or stacks of unsold finished products, there is the waste of Inventory.

Tools to battle Inventory waste:

• Purchasing only when need and in proper quantity
• Reducing buffers between steps
• Use a Kanban or pull system to control finished goods

Waste of Transportation

The waste of Transportation is the moment of inventory, equipment, tools, people, or products further than is necessary.  Transportation waste can be difficult to categorize since your customer only cares about the final delivery, but some transportation is necessary. The waste of Transportation is the excess moment of resources not required by the process.  Just as the shortest distance between two points is a straight line, there exists the shortest transport distance in any process.  When a raw material staging area is not near the receiving dock or the finished goods queue is separated from the shipping dock, Transportation waste exists. Having to move work in process from department to department when a simpler cellular production arrangement could be employed is waste of transportation.

In an office, transportation waste can be the moment of files or binders from desk to desk, people traveling to a central conference room for meetings, natural work teams separated be physical distance into departments.  Even something as commonplace as the office copier can introduce transportation waste is it is located away from its most frequent users.

Tools to battle Transportation waste:

• Create an efficient workflow through Process Maps or Spaghetti Diagrams
• Organizing processes into functional work cells
• Plan processes around “monuments” that cannot be relocated

Waste of Motion

The next waste that we will examine is the waste of Motion. It is the unnecessary movement of people, machinery, or equipment.  This includes walking, reaching, lifting, bending, and moving in people as well as excessive motion in tools and machines.  Motion waste can range from reaching for frequently used tools, to stacking products on a pallet, to walking to gather more raw materials.  Each process has required motions, but excess motion makes up a substantial part of any process which has not been standardized.  In standardizing a process, it is important to consider ways to reduce excess motions which will improve safety and consistency.

In an office, motion waste can be turning in a chair to open a file cabinet, reaching to answer the telephone, looking back over a shoulder to answer a question.  It is the combination of many small motions over the course of a day which contributes to worker fatigue.

Tools to battle Motion waste:

• 5S to organize the workplace
• Ergonomic design of workstations and processes
• Standard work which reduces excessive motions

Waste of Waiting

The waste of Waiting is people waiting on materials or work to do and equipment that is idle, losing its productive capacity.  Waiting is often caused by unevenness in the production process with excess inventory and work in process in some areas and waiting in others.   Waiting waste can also be caused by upstream processes that are unreliable due to breakdowns or quality issues.  The waste of Waiting maybe people slowing down in their process in order not to complete the available work and being forced to wait.  Waiting waste is quickly highlighted whenever a critical piece of equipment fails and requires maintenance.  The waiting becomes very evident on the downstream processes that rely on that equipment.

In an office environment, waiting waste includes items like waiting on an email response or decision, having files waiting for review, waiting on the end of a meeting to speak with one of the attendees, and waiting on software to load. Waiting waste is such a common waste in everyday lives, that we often do not give it serious consideration in the workplace.

Tools to battle Waiting waste:

• Balancing processes using Takt Time
• Improving equipment uptime using Total Productive Maintenance
• Flexible multi-skilled workforce to rapidly adjust to work demands

Waste of Over-Processing

The waste of Over-Processing refers to doing more work, adding more features, or having more steps in a product or service than what is required by the customer.  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 the customer asked for, additional options not called for in the function.  Certain cleaning steps and some packing can be classified as over-processing wastes.  Also, product documents in multiple languages or excess parts required for assembly maybe examples of the waste of over-processing.

In an office, over-processing can include more detail or data in a report than is required, unnecessary approvals, extra steps required in the purchasing process, and having an extra step in a workflow for information purposes.

Tools to battle Over-Processing waste:

• Understanding of Customer Requirements, Voice of the Customer
• Value Engineering and Value Analysis
• Standard Work which focuses on Value Add

Waste of Defects

The waste of Defects is when a product or service is not fit for its intended use.  Defective products generally have two remedies, either rework or scrap. Both rework and scrap are wastes in that there are direct additional costs to operations which generate no value to the customer. The waste of Defects has compounding consequences beyond the operations costs.  Defects can lead to delays in delivery or worse yet, defective products can escape and be delivered to the customer, causing additional costs, and hurting the company’s reputation. A rule of thumb for the cost of quality is that the actual cost is multiplied by a factor of ten when defects escape to the customer.

In an office defects include things like spelling and grammar errors in documents, delivery of the wrong files requested, and incorrect invoicing.  Every person in an office has a customer, whether external or internal and the waste of defects impacts both.

Tools to battle Defect waste:

• Pareto charts to identify the “vital few” errors to address first
• Poka yoke, or mistake proof, processes to stop or detect defects at each step
• Jidoka, intelligently designed machines or process to eliminate the chance of defects

The Added on Waste: Waste of Unused Human Skills

The last waste was not part of the Toyota Production System, but was recognized and adopted into Lean Manufacturing, is the waste of unused human Skills.  This waste occurs when companies do not recognize the skills each employee possesses. When ideas are only top down, when people are told that they are here to work not think, or when solutions to problems are handed to workers without using their input to develop those solutions.  The waste of Skills is present when an organization does not understand that those most capable of solving the problems are the people with the most experience dealing with them.

In an office environment, the waste of Skills is the same as in a manufacturing setting. People can think clearly and solution their problems, but they may need the training and resources provided by individuals higher in the organization’s structure.

Tools to battle Skills waste:

• Training and cross-training in their job and jobs of their team
• Teamwork, collaborative problem solving
• Leadership which empowers the creativity of all team members