When NOT to Use Kanban: Common Mistakes to Avoid

Kanban is a powerful tool to manage materials using pull logic, improving both the efficiency and responsiveness of the supply chain.
However, it is not a universal solution. Its application must be carefully evaluated, because there are contexts where Kanban does not work—or can even make the situation worse.

In this article, we analyze the main mistakes companies make when they decide to apply Kanban without the necessary preliminary analysis or without proper system design.

1. Applying Kanban Without Involving the Supplier

One of the most common mistakes is to implement a purchase Kanban without informing the supplier.

The result?
The card is released, but the supplier is unaware of the new method and continues to work with standard orders or on-demand requests.

This happens because of the absence of:

• Formal agreements (e.g., open orders or framework contracts)
• Supply specifications with management rules
• Material labeling according to Kanban logic
• Kanban identifier included in the delivery note (DDT)

Without structured collaboration, the Kanban flow will naturally be ignored or bypassed, causing stockouts and urgent situations, since the supplier is not in a position to organize its processes (production capacity and materials).

2. Using Kanban with Erratic or Seasonal Consumption

Kanban works well in contexts with stable, repetitive consumption.

When consumption is strongly affected by peaks, variable trends, or seasonality, the system often collapses:

• During peaks → sizing becomes insufficient → stockouts
• During declines → inventory increases → waste and tied-up capital

3. Oversizing Cards “Out of Fear”

Many companies, for “safety,” set inflated stock levels when launching the system.

The result is an oversized Kanban that:

• Slows down warehouse turnover
• Increases occupied space
• Locks in capital unnecessarily

Kanban sizing should never be improvised: it must be calculated scientifically on a statistical basis and updated over time.

4. Applying Kanban Rigidly and Uniformly

Another common mistake is to apply the same “one-size-fits-all Kanban rule” to all items.

Each code, however, has its own logistical and production characteristics.

Example:
If a code requires sheet metal cutting operations, the card quantity must be adjusted based on sheet optimization (nesting), not only on the statistical daily consumption.

5. Replacing MRP with Kanban Without Criteria

A serious mistake is to believe that MRP can be completely replaced with Kanban without first carrying out the necessary analysis and decisions.

The two systems are not competitors but complementary.

Kanban should only be applied to materials that:

• Have constant consumption
• Have stable lead times
• Are suitable for pull management

For all others (e.g., items with irregular demand, spot purchases, etc.), MRP or push logic is still more appropriate.

6. Leaving the Kanban System Without Maintenance

A Kanban that is properly sized today may no longer be valid in a few months.

Why? Conditions change:

• The production plan changes
• Suppliers or lead times change
• Demand changes

If the system is not maintained with appropriate tools (e.g., automatic update proposals as in KanbanRocket), companies risk:

• Understock for growing items
• Overstock for declining items
• Total loss of efficiency

7. Cultural Resistance (Rare, But Still Present)

Some operators or suppliers, unfamiliar with the pull method, tend to ignore or bypass the Kanban system:

• They replenish “by eye”
• They withdraw without releasing cards
• They ship goods without respecting the per-container quantities

Today this is increasingly rare, but in less mature contexts, it is still a risk.

Conclusion

Kanban is an effective tool, but only if it is properly and consciously designed.

Before introducing it, it is essential to:

• Classify materials (e.g., with an ABC-RRS analysis)
• Verify operational feasibility
• Involve all stakeholders (customers, suppliers, operators)
• Design the system scientifically
• Ensure continuous maintenance

👉 An improvised Kanban will not work.
A well-designed Kanban is a powerful lever to eliminate emergencies, reduce inventory, and streamline flows.