Was This Inventory Built Intentionally—or Did It Just Accumulate?

Was This Inventory Built Intentionally—or Did It Just Accumulate?

Taiichi Ohno, the father of the Toyota Production System, was known for asking simple but penetrating questions at the genba.

When he encountered inventory, he asked:

Was this inventory created intentionally, or did it simply accumulate?

At first, this may sound like a straightforward question about materials. In reality, it challenges leaders to examine how decisions are made throughout an organization.

Is what we see the result of a deliberate choice? Or is it the unintended outcome of habits, incentives, assumptions, and disconnected processes?

The question matters because inventory does not appear by itself. Something in the system produced it, moved it, ordered it, or allowed it to remain.

To understand inventory, we must understand the intention—or absence of intention—behind it.

If the Inventory Was Intentional, Understand the Purpose

Suppose the inventory was created intentionally.

That answer should lead to several additional questions:

What was the intention?

Who made the decision?

What problem was the inventory intended to solve?

Was the decision based on facts or assumptions?

Was the intention appropriate at the time?

Is it still appropriate today?

What conditions influenced the decision?

What risks was the organization trying to avoid?

Inventory may have been produced as protection against equipment breakdowns, long changeover times, supplier delays, quality problems, demand fluctuations, transportation risks, or unreliable production schedules.

For example, a team may hold extra components because a supplier frequently delivers late. Another department may create work-in-process inventory because the next operation is unreliable. A production manager may authorize larger batches because changeovers take too long. A planner may order excess materials because demand forecasts are inaccurate.

In each case, the inventory has an intention. It is acting as protection against uncertainty.

That does not automatically mean the inventory is justified. It means the inventory is connected to a problem that must be understood.

Simply removing the inventory without addressing the underlying condition can make the operation unstable. If the organization eliminates safety stock while supplier performance remains unreliable, shortages may follow. If work-in-process is reduced without improving equipment reliability, production interruptions may increase.

The objective is not to eliminate inventory blindly.

The objective is to understand why people believe the inventory is necessary—and then improve the conditions that created that belief.

Whose Intention Is It?

It is also important to ask who created the intention.

The inventory may make sense from the perspective of one department while creating problems for the rest of the organization.

A production department may build extra units to maximize equipment utilization. A purchasing department may order large quantities to receive a volume discount. A logistics team may prefer full truckloads to reduce transportation costs. A sales team may request additional finished goods to protect against uncertain customer demand.

Each decision may appear rational when evaluated locally.

However, what is efficient for one department may be inefficient for the overall system.

A lower purchase price may lead to higher storage costs, increased handling, greater risk of obsolescence, and more working capital tied up in materials. Higher equipment utilization may generate products that customers have not ordered. Full truckloads may reduce transportation cost per unit while extending lead times and increasing inventory.

This is why the question “Whose intention?” is so important.

Organizations often create waste not because people are careless, but because they are responding logically to narrow goals, local measurements, or conflicting incentives.

If performance systems reward production volume, people will produce more. If purchasing teams are evaluated primarily on unit cost, they will favor larger orders. If managers are rewarded for keeping employees and machines busy, stopping production may appear unacceptable—even when there is no customer demand.

The visible inventory may therefore be the consequence of an invisible management system.

Most Inventory Has No Clear Intention

The uncomfortable truth is that much of the inventory found in organizations was never consciously designed.

It accumulated.

Production continued because the machine was available. Materials were ordered because the forecast suggested they might be needed. Extra items were stored because nobody had the authority to remove them. Work moved forward because employees believed that staying busy was more important than responding to actual demand.

Over time, the exceptional became normal.

A temporary buffer became a permanent storage area. A one-time overproduction problem became part of the monthly plan. Materials purchased for a discontinued project remained in the warehouse because ownership was unclear.

Eventually, nobody could explain why the inventory was there.

People might still offer explanations:

“We have always done it this way.”

“We might need it someday.”

“It is more efficient to produce a larger batch.”

“We cannot risk running out.”

“The system told us to make it.”

“We had extra time, so we produced ahead.”

These explanations often describe habits, fears, incentives, or assumptions—not the true cause of the inventory’s existence.

When nobody can clearly explain what triggered production, who authorized the quantity, or what customer need it serves, the inventory is not being managed. It is simply occupying space and absorbing resources.

Inventory Is Evidence

Inventory should not be viewed only as material.

It is evidence.

It tells us something about how the system operates.

Excess raw materials may indicate poor supplier reliability, inaccurate planning, or purchasing incentives based on volume discounts. Work-in-process may reveal unbalanced operations, long changeovers, equipment instability, or disconnected production schedules. Finished-goods inventory may point to forecast-driven production, overproduction, or weak communication with customers.

Inventory can also conceal problems.

When large buffers exist between processes, delays and defects remain hidden. An operation can continue producing even when the next process is struggling. Defective products may sit unnoticed in a queue. Equipment problems may appear less urgent because extra inventory protects downstream operations. It signals a serious lack of trust between the processes.

The buffer allows the organization to continue functioning, but it also prevents the organization from confronting the true weakness.

Inventory is often compared to water covering rocks. The water represents inventory, while the rocks represent operational problems. As long as the water level remains high, the rocks stay hidden. When inventory is reduced carefully, the problems become visible.

The purpose is not to lower the water recklessly and crash into the rocks. It is to expose one problem at a time, solve it, and then continue improving.

Visualize the Intention: Kanban

Kanban makes the intention behind production and movement visible.

A Kanban signal communicates that something is needed, in a defined quantity, at a particular time and location. It creates a connection between actual consumption and replenishment.

Without a clear signal, production can easily become disconnected from demand. People produce because they have capacity, because the schedule says so, or because stopping feels inefficient.

Kanban introduces a fundamental discipline:

Do not produce, replenish, or move something without a clear reason.

This is why Kanban is more than a scheduling card, board, container, or software tool. Its deeper purpose is to make authorization visible.

A Kanban answers several important questions:

What needs to be replenished?

How much should be produced or moved?

Where is it needed?

What consumption triggered the action?

Who is responsible for responding?

What is the limit?

When the signal is visible, the intention is visible.

If production occurs without a Kanban or another clearly defined authorization, the abnormality can be recognized immediately. The organization can then ask why the rule was bypassed and what condition caused the deviation.

Kanban does not merely control inventory. It connects action to demand and exposes production without a valid purpose.

Visualize the Limits: 5S

Every workplace also needs visible limits.

Where should materials be stored? How many are permitted? What belongs in each location? How long should the items remain there? What condition should the area be in?

These questions reflect the deeper purpose of 5S.

5S is often misunderstood as a cleaning or housekeeping activity. Cleanliness matters, but 5S is fundamentally about creating a workplace in which normal and abnormal conditions can be distinguished immediately.

A clearly designated location communicates where an item belongs. A labeled container identifies what it contains. A marked floor area defines the available space. Minimum and maximum levels establish acceptable quantities. A visual standard shows the expected condition.

When these limits are visible, excess inventory can no longer blend into the environment.

If ten containers are permitted and an eleventh appears, the abnormality is obvious. If materials remain outside the designated location, someone can ask why. If obsolete items occupy space needed for current work, the conflict becomes visible.

Without limits, accumulation can continue indefinitely.

An open floor becomes storage space. An empty shelf attracts unused materials. A temporary staging area becomes permanent. Because no boundary has been defined, nobody can say with confidence that the condition is abnormal.

5S gives the workplace a clear voice. It enables the environment itself to indicate when a standard has been exceeded.

Keep Questioning the Intention: Kaizen

Visual controls and standards are essential, but they should never end the discussion.

A standard reflects the best-known method under current conditions. It is not a permanent truth.

Teams must continue asking:

Is this inventory still necessary?

Does the original reason still exist?

What problem is the inventory protecting us from?

Can we remove or reduce that problem?

Can we reduce the quantity safely?

Can replenishment happen more frequently?

Can changeover time be shortened?

Can supplier reliability be improved?

Can quality problems be detected earlier?

Can information flow more directly?

Is there a better way to meet the customer’s needs?

That continuous questioning is Kaizen.

Kaizen is not simply collecting improvement ideas or running occasional workshops. It is the disciplined practice of challenging current conditions, testing assumptions, and learning through repeated experimentation.

For example, if a process holds two days of inventory because of frequent equipment failure, the team should not merely debate whether two days is too much. It should investigate the failures, improve preventive maintenance, and then test whether the buffer can be reduced safely.

If large production batches are justified by long changeovers, the team should study the changeover process. By separating internal and external activities, preparing tools in advance, and simplifying adjustments, changeover time may be reduced. Smaller batches then become practical.

The inventory level should improve because the process capability improved—not because management simply ordered people to reduce it.

The Danger of Arbitrary Inventory Reduction

Leaders sometimes see excess inventory and immediately demand a fixed percentage reduction.

This may improve a financial metric temporarily, but it does not necessarily improve the system.

If inventory exists because of unstable equipment, poor quality, unreliable suppliers, or long replenishment times, an arbitrary reduction can create shortages and emergency work.

Employees may respond with expediting, overtime, hidden buffers, and unofficial workarounds.

The visible inventory declines, but the underlying problems remain.

Worse, people may learn to hide inventory rather than improve the process.

Effective inventory reduction must be connected to cause removal. As reliability improves, buffers can be reduced. As changeovers become faster, batches can become smaller. As quality improves, less protection is required. As lead times shorten, less material needs to be held.

Sustainable results come from improving the system—not manipulating the number.

The Principle Extends Beyond Manufacturing

This way of thinking applies far beyond physical inventory.

Every organization accumulates things.

Offices accumulate reports, spreadsheets, approvals, meetings, emails, policies, dashboards, software tools, projects, and administrative processes. Digital work may not occupy warehouse space, but it still consumes time, attention, money, and capacity.

A weekly report may have been created years ago for a leader who has since left the organization. A recurring meeting may continue even though the original project has ended. An approval step may remain after the risk it addressed has disappeared. A software subscription may continue because nobody owns the decision to cancel it.

The same questions should be asked:

What is the intention?

Who needs this?

What decision does it support?

What risk does it control?

Does that need still exist?

What would happen if we stopped?

Is there a simpler way to accomplish the purpose?

If nobody can explain the purpose, the activity may be organizational inventory—work that has accumulated without a clear connection to value.

Intention Is a Leadership Responsibility

Leaders shape the conditions that create inventory.

They establish targets, incentives, measurements, approval processes, and decision rights. If those systems encourage local optimization, employees will make locally rational decisions that create organization-wide waste.

Therefore, leaders should not begin by blaming the people closest to the inventory.

They should examine the system.

What behavior do current metrics encourage? Is production rewarded even when there is no demand? Are people afraid to stop a machine? Does purchasing receive recognition for discounts while inventory costs are ignored? Are teams punished for shortages but never questioned about excess?

Inventory often reflects what management has chosen to measure and reward.

Leadership’s responsibility is to create an environment in which purpose, demand, standards, and limits are clear. People should be able to explain why work is being done, who needs it, what authorized it, and when it should stop.

Go to the Genba and Ask

Reports can show how much inventory exists, but they rarely explain why it exists.

To understand the cause, leaders must go to the genba.

They should observe the work, speak with the people performing it, examine the flow of materials and information, and ask questions without immediately assigning blame.

Useful questions include:

What caused this material to be produced?

What customer or process requested it?

How was this quantity determined?

How long has it been here?

What prevents us from using it?

What problem would occur if it were removed?

What standard defines the acceptable quantity?

When was that standard last reviewed?

What conditions would allow us to reduce it?

The purpose of these questions is not to catch someone making a mistake. It is to understand the thinking and conditions that produced the current situation.

When leaders ask respectfully and persistently, inventory becomes an opportunity to learn about the entire management system.

Make Intention Visible

Operational excellence begins when organizations stop accepting accumulated conditions as inevitable.

Every item, task, report, meeting, approval, and process should have a purpose. That purpose should be connected to customer value, safety, quality, delivery, cost, or another clearly understood organizational need.

If something was created intentionally, make that intention visible.

If the original intention is no longer valid, remove it.

If the intention is valid but the solution creates waste, find a better method.

If nobody can explain why something exists, investigate rather than accepting it as normal.

Visualize the intention through Kanban.

Visualize the limits through 5S.

Keep questioning the intention through Kaizen.

The goal is not merely to reduce inventory. It is to build an organization in which actions are deliberate, abnormalities are visible, and people continually question whether current practices still serve their intended purpose.

When intention becomes visible, Muda becomes easier to recognize.

When limits become visible, abnormalities become harder to ignore.

When intentions are continuously questioned, meaningful improvement can begin.