Even if you have only heard of the concept of Lean thinking, you know that Lean is all about waste elimination.

Within the Lean framework there are three kinds of waste: muda, mura, and muri.

Muda, or physical waste, is our focus today. Of the three sources of waste, muda is the easiest to quantify and discuss.

It is also the kind of waste that management professionals and decision makers from a variety of industries will most readily understand and relate to.

As a quick aside, mura is waste that is generated by unevenness of flow. Muri is waste that is generated by overburden. Both are key aspects that Lean-minded decision makers in the manufacturing sphere must be conscious of.

Click or tap to enlarge

Together, muda, mura, and muri all represent the broad categories of waste that can bog down and incur cost within an organization’s operations. Continuous waste elimination efforts are the best defense against inefficiency and the erosion of value for the customer.

Before we begin identifying and qualifying our sources of physical waste, let’s take a bird’s-eye view of one of the key Lean philosophies: visibility.

Visibility as a Lean Philosophy

Visibility is one of the core components of Lean thinking.

The logic of high-visibility operations is as follows: if waste events go undetected they cannot be rectified. This means that operations will be incurring cost that cannot be passed on to the customer.

Within Lean organizations this is classified as waste, and it is a cardinal sin.

Visibility is more than just organizational transparency.

Within Lean organizations, visibility is an enabling factor for so many other activities.

Visibility leads to action. Waste events that are permitted to go on undetected may do so indefinitely. Once uncovered, however, they can be addressed through corrective action.

In this way, an organizational focus on visibility enables a culture of aggressive waste elimination.

Visibility is also an enabling factor to a culture of continuous improvement, also known as kaizen within the Lean framework.

Just like the hidden waste events, inefficiencies that often plague organizations are harder to correct if they remain undetected.

Referred to as innovation, the continuous incremental changes that propel Lean organizations to enviable levels of efficiency are enabled by a high degree of organizational visibility.

Visibility also enables organizational foci on simplicity, maintaining a broad view, and flexibility—all of which are also key components of Lean philosophy.

DOWNTIME & Waste Elimination

Downtime is the enemy of production operations.

It is also an acronym used to recall the eight sources of muda, or physical waste. To review, muda is one of the three sources of waste within operations. DOWNTIME encompasses the eight sources of physical waste that make up muda.

D.O.W.N.T.I.M.E. stands for

Defective production

Overprocessing

Waiting

Non-used employee talent

Transportation

Inventory

Motion

Excessive production

Let’s dive in to each of these for a closer look.

Downtime is an acronym that represents the eight sources of waste within the Lean framework: defective production, overprocessing, waiting, non-used employee talent, transportation, inventory, motion, and excessive production. Visibility within an organization’s operations and supply chain is crucial to waste elimination efforts, as visibility acts as an enabler to uncover the sources of waste.

Defective Production

Defective production is the most easily recognizable source of waste.

Any production incurs cost; however, production should also produce value. Value is best described as cost that can be passed on to the customer. Defective production incurs cost that not only cannot be passed on to the customer but also generates other waste events.

Defective production must be committed to scrap or rework, meaning it must be transported, stored, and run through the whole processing sequence again.

These are all activities that incur cost that cannot be passed on to a customer.

Defective production not only wastes resources and time, but spawns other waste events that further compound losses.

If we own a company that produces widgets and a batch is found to be defective, that same batch could potentially be run through complete production one more time. In the eyes of the customer, it doesn’t matter if those widgets were run through production a dozen times; they are only paying for the value.

Overprocessing

Everyone is looking for more features. Every customer wants all the bells and whistles.

For production operations, however, one bell or whistle too many is a waste event.

Providing the highest level of value for the customer should be at the forefront of all production operations. The important thing to remember about overprocessing is that customers will only pay for the features they asked for.

If a part or a product receives more processing than a customer asked for, that additional work is waste. It is not cost that can be passed on to the customer. It does not provide value.

Waiting

When goods are not being processed, consumed, or in transport, they are assigned the “waiting” status.

Any time spent in waiting is non-value-added.

If a part spends ten hours waiting or ten minutes, the cost of that time cannot be passed on to the customer.

If the cost can’t be passed on, then it is waste and should be eliminated.

Non-Used Employee Talent

This somewhat clunky term has been adopted to make the DOWNTIME acronym work, but the concept is clear.

Innovative ideas can come from anyone within an organization.

The cost associated with underutilized employee talent is best described as an opportunity cost.

Therefore, it can be difficult to quantify.

Here visibility enables innovation by allowing as many members of the organization as possible to see operations in their entirety so that their kaizen suggestions are tailored to the actual state of operations.

Employee participation in operations and organizational success has the added benefit of giving those employees a sense of ownership within their organization.

This sense of ownership makes staff at all levels committed to success, because they are co-opted as stakeholders in growth, efficiency, and waste elimination.

Transportation

Transportation is a non-value-added activity.

Delivery is the only transportation that the customer will pay for.

Like waiting, defective production, or overprocessing, it doesn’t matter if a part has been transported forty miles or forty feet—a customer won’t accept the costs for any transportation other than delivery.

Transportation can be an inevitable cost. Parts must be moved between workstations. Raw materials must be fed into the production process. Finished goods must be loaded onto delivery vehicles. These are all instances of transportation that incurs cost. It is value-added, however; manufacturers cannot provide value without moving goods through the production process.

Minimizing transportation activities not only means reducing non-value-added activities (waste), it also means reducing the risks of other transportation-related waste events.

The more parts, products, or components are moved around, the higher the chances of damage or misplacement.

Inventory

Inventory in all forms represents income that has not been realized.

Waste events related to inventory include issues stemming from the three key manufacturing inventories:

  • Raw materials
  • Work in progress
  • Finished goods

On-hand inventories incur cost without directly generating revenue.

A customer doesn’t care if a part spent five minutes in a warehouse or five months. If the duration was the latter, that was five months of occupied space and incurred cost for the company.

Changing from traditional inventory-carrying methods to a Lean-inspired Just-in-Time (JIT) inventory and production method is no small feat. It requires a complete deconstruction of an organization’s supply chain with full support from management.

Despite the challenges associated with transitioning to JIT methods, the savings in the form of reduced cost and minimized waste are enviable.

Motion

Motion as a source of waste represents wasted work in the literal sense of the word.

Non-value-added motion is any wear and tear not strictly needed for value-added production.

Productive motion, or the wear and tear on production tools that generates value, can be passed on to customers.

Motion that doesn’t produce value, however, cannot be passed on to customers.

Motion as a source of waste is often the product of another waste event. Overprocessing consists almost entirely of wasted motion. Defective production produces non-value-added motion through scrap or rework.

Of course, redundancies in production processes also produce standalone wasted motion, so decision makers shouldn’t always assume that their processes are free of wasted motion.

Excessive Production

Wasteful production is distinct from overprocessing in the sense that it is production that meets (but does not exceed) customer specs. The source of waste is the fact that too many parts were produced.

Excessive production is when production exceeds customer demand.

Lean manufacturing revolves around the concept of small batch production. This, in turn, reflects the flexible nature of Lean.

The takeaway when studying excessive production as a source of waste is this: a customer will not pay for more finished goods than they need. This means that every part or product produced past the customer’s needs is wasteful production.

The Bottom Line

A common thread within the Lean framework is the way in which soft skills and concepts (philosophies) interact with concrete best practices (such as Just-in-Time, takt time, etc.).

This comes up time and time again.

Each of the concepts that make up the Lean framework works in unison with every other Lean element, enabling and supporting the same goal to produce a framework that is larger than the sum of its parts.

Lean thinking is not a cure-all that will fix every problem a given organization faces.

It is, however, a successful approach to waste elimination and organizational excellence that has been proven time and time again to be powerful, effective, and results-oriented.

Even if none of the concepts of Lean thinking are directly applied to a given organization, critical consideration of Lean elements can lead to the kind of innovation that produces market-making competitive edge.

This article was sourced in part from the bestselling book Lean: QuickStart Guide – The Simplified Beginner’s Guide To Lean published by ClydeBank Media.

The next steps to take:

  1. If you found this post helpful, take a moment to share it. Even better, tell us in the comments!
  2. Continue exploring the world of Lean thinking and process optimization with these helpful posts:

Fishbone Diagrams are the structured investigative tool you didn’t know you needed.

The Future of Lean 

What is Six Sigma?