Flow or Process?

“We are not Toyota; our sector is different.” I hear this objection often. Of course it is different. The products, demand, technology and order structure are not the same. Copying another business’s solution unchanged would not be appropriate.

Yet there is a question we can ask in every business: which steps does the customer’s need pass through from order to delivery, and where does it wait?

What does improving a process achieve?

Reducing setup time through SMED, balancing work through Yamazumi, developing standardised work, reducing maintenance losses… Each can address a particular problem.

Improvements in safety, quality and ergonomics are also valuable; they do not necessarily have to shorten flow time. But when we speed up a machine, we must separately assess how this affects total output.

What does flow show us?

If work-in-process before or after a machine grows while the machine runs faster, the local gain may not benefit overall flow. A station’s capacity is not the same as the quantity we can deliver to customers.

We therefore need to track waiting, processing times, inventories and delivery results together at product-family level. Speeding up work without seeing the bottleneck and material replenishment system may merely move the queue elsewhere.

Let us name the times correctly

D2D is the defined door-to-door lead time of the production system. Order-to-delivery and order-to-cash times have different scopes. Days of inventory is a separate measure showing how long available stock covers average consumption. [1]

Management should understand how these measures affect one another, while shop-floor teams should be able to solve specific process problems. We connect process improvement to the needs of the whole system.

You do not have to be Toyota. You need to see an order’s journey through your own business and improve that journey together.

[1] Lean Enterprise Institute · Cycle Time and Production Lead Time