SMED: How Rapid Changeovers Create Flexibility and Flow

SMED: How Rapid Changeovers Create Flexibility and Flow in Construction

When I talk about SMED, I am talking about Single Minute Exchange of Die. I first learned this on a lean trip to Japan with Paul Akers. In construction we often say SMET, Single Minute Exchange of Task. Today I want to share how this concept was taught to me, the remarkable things I saw firsthand, and how I am applying it in my work with phenomenal results. You are going to love this blog.

Understanding Single Minute Exchange of Die

Single Minute Exchange of Die originated from a powerful need. In United States manufacturing history, Henry Ford was a pioneer. During World War II his team created a Liberty ship every 60 minutes. One ship per hour. That is incredible. The mass production model worked beautifully in a high demand environment with large spaces and economies of scale.

Japan had a very different reality. Their factory sizes were smaller. Demand was lower. Variation was higher. They could not mass produce ten thousand of one model and wait for buyers. Instead, they might receive an order for seven hundred fifty Camry’s and then four hundred units of a different vehicle. They did not have separate plants for every variation. They needed to change machinery and dies quickly. They also did not have the money or space to hold massive amounts of inventory.

This constraint became a gift. It led to the development of Just in Time and ultimately SMED.

Why Japan Needed SMED

If you only produce what is needed when it is needed, you must be able to switch over fast. Imagine producing seven hundred fifty Camry’s with slightly different trim or dash layouts. If it took an hour to change dies, the temptation would be to overproduce the first variation. That creates excess inventory. Excess inventory creates transportation. Transportation creates defects. The entire system begins to spiral into waste.

SMED broke that spiral. It allowed Japanese manufacturers to switch from one product to another in under ten minutes. This kept production aligned with demand and prevented all seven wastes from cascading.

An Incredible SMED Example

We visited a company in Mifune that supplies parts to Toyota. Inside were six massive stamping machines with dies that weighed thousands of pounds. Paul timed the changeover for us. When a machine hit its quota, the team shut it down and began a full die exchange.

They had rail lines under each machine. When the machine stopped, a cart slid in. A panel dropped to create a roller tray. The old die slid out naturally with no motors or cranes. A second cart brought in the new die. It rolled into place. The machine reset. Then the process repeated down the line.

In six minutes all six huge dies were changed. The machines were stamping new parts. The entire line was running. The operators were tuned in like an orchestra. Paul narrated each machine clicking back online.

I used to think SMED meant one minute. It actually means single digit minutes. Anything under ten. Watching those operators run the entire line again in six minutes was one of the most impressive things I have seen in lean manufacturing.

Why Slow Changeovers Hurt Construction

When changeovers are slow, people overproduce. Overproduction creates excess inventory. Excess inventory leads to defects, over-processing, transportation, motion, and waiting. In short, slow changeovers destroy flow.

And here is the important part. Changeovers are not always about dies. They are about tasks.

What is our die in construction?

It is the moment we switch.
From a meeting to production work.
From a field walk to a pull plan.
From planning to executing.
From one task to the next.

Every time we switch contexts, if it takes fifteen or twenty minutes to reset, we lose flow.

Single Minute Exchange of Task

In construction trade partners often say they want the whole building or the whole floor. The real reason is that they do not have SMET. They do not have a fast, repeatable, efficient way to switch tasks.

Imagine a fire sprinkler contractor saying they want to install all mains through the entire building at once. That is batching. It slows everyone else down and tanks the schedule.

But imagine instead that they have a mainline installation cart. When they finish in one zone, they can switch the cart to install branch lines in under two minutes. That is SMET. Zone to zone to zone. No batching. No friction. No overproduction. Just flow.

Your Challenge

Identify your change points. Where do you switch tasks, phases, or mental focus? Where does friction slow you down?

Then ask, how can we reduce that changeover to under ten minutes?
How can we get close to one minute?
How can we create Single Minute Exchange of Task?

We have applied this in our remote consulting business with great success. It applies everywhere in construction and everywhere in your personal work systems.

A Final Thought

Frederick Taylor separated crafts so deeply that crews lost their ability to switch tasks smoothly. But historically carpenters handled rough carpentry and then finish carpentry. All they needed was to change their bags and tools. That was SMET in real time.

We need more cross training. We need more multi skilled crews. We need fast task switching. And we need systems that protect flow.

Find one place today where you can implement this. Then watch what happens.