The practice of leaning the supply chain until it’s whip-thin has lost favour in recent years, but that doesn’t mean that certain lean tools and principles are obsolete. In fact, many of them can be put to excellent use in the small-business supply chain to root out and eliminate waste and non-value-adding process-steps.

In our post today, you can learn about a couple of lean tools that are easy to put into practice and can be used in just about any area of your supply chain. The first lean tool we’ll explore is one so simple a child could use and is just perfect for getting to the root-cause of supply chain problems.


Give the 5 Whys a Try

The 5 Whys is an iterative problem-solving technique that’s literally child’s play to use. If you’re a parent you’ll know that indeed, children are experts at asking “why” “why” and “why” again—which in essence, is all you need to do to solve problems with this lean supply chain technique.

Of course the 5 Whys process doesn’t have to be used only in the pursuit of leanness. Like many lean tools, it can be applied in any situation where there’s a problem that needs solving. It needs no special equipment, skills or software, but a notepad might be a good idea to record your discoveries.


Use the 5 Whys to understand the root cause of a problem, or to get to the bottom of why a process is carried out in a certain way.


For example, you might ask something similar to the following:

  • Why are seven out of ten deliveries to route-trade “customer X” arriving late?
  • Why don’t we have end-to-end visibility of our supply chain?
  • Why must product X be manually stacked onto pallets instead of being auto-palletised like all other SKUs?

These are just some hypothetical examples of questions with which to begin the 5 Whys technique. After asking the initial question, you will have some sort of an answer, but that’s just the beginning of the learning process.

For instance, the answer might be that seven out of ten deliveries to customer X are arriving late because customer X is always planned as the last delivery on an urban route, on which traffic delays often hold up the driver.


So now you would ask why again. In our example, you could ask “why is customer X always planned as the last delivery on the route?”


The answer might be “because although the customer’s store is close to our DC, the customer will not take deliveries early in the day, so we can’t make the delivery first on the route.”

Next question: “Why won’t the customer take deliveries early in the day?”

Answer: “Because he has no unloading slots available in the morning, and we’re not a major supplier to him, so he won’t prioritise our deliveries.”


5 Whys: Give or Take a “Why” or Two

Now although the technique is called the 5 Whys, we’ve reached the point in our example where we have the root cause of our problem.

After all, we can’t really ask why we’re not a major supplier, because we probably already know the answer to that, and the problem is with late deliveries, not our importance as a supplier.

We can’t really ask why the customer has no unloading slots either, because that would be quite a hostile challenge to the customer. So in this case, it has taken only 3 Whys to get as close to the root-cause as possible. What we can do now though, is consider what might be done to prevent our deliveries from being late.


“Why” is the Way to Wisdom

Before asking the 5 Whys, we knew only that the deliveries were arriving late. We did not know the root-cause. We also know, from asking our questions, that the delivery route is one commonly affected by traffic delays, and that our customer is close to our distribution centre. So now we have the wisdom to seek solutions that fit the framework of these conditions.


The 5 whys is a way to find solutions which will last, because they address the cause of the problem instead of the just the symptoms.


In our example, the causes of the problem are the constraints placed by the customer. If we hadn’t used the 5 Whys lean tool, we might try to stop the customer’s deliveries from being late by a process of trial and error, perhaps making the situation more troublesome, or by falling back on costly quick-fixes such as expedited delivery.


Prevent Errors with the Poka-yoke Lean Tool

The famous seven wastes of transport, inventory, motion, waiting, over-production, over-processing and defects often originate from human error. Errors might create extra travel and transportation, cause unwanted waiting time and delays, and are certainly a common cause of defects.


Whether you use lean tools like the 5 Whys or some other method, discovering human error at the root of a problem should be cause for celebration, not concern, because errors can be prevented.


While the 5 Whys is a lean tool for discovering the causes of waste, poka-yokes are lean tools for waste-elimination. Poka-yoke solutions are physical measures to prevent process-errors. They can be mechanical, technological, or even visual in nature.


Like the 5 Whys, Poka-yoke solutions can be used in just about any process, making them worthy of consideration anywhere that human-error can create waste.


In your warehouse for example, you might consider poka-yoke solutions to prevent picking errors, which typically result in:

  • Unnecessary travel or transportation (to put incorrectly picked products back into bins and then pick the correct product)
  • Waiting (if picked orders must be checked for correctness, the time taken to perform the checks might delay the loading of trucks)
  • Defects (if an incorrectly picked order is received by a customer, the delivery can said to be defective).

Some possible poka-yoke solutions to reduce or eliminate picking errors might include:

  • RFID scanning on the route between pick faces and marshalling areas/loading docks
  • System-guided picking using Barcode scanning and/or pick-by-voice
  • Smart location of similar-looking products so that they are not close to one another on the picking route


Poka-yoke solutions can be extremely simple or highly complex, but if you look hard enough, there are always opportunities to use this ingenious method to stop mistakes being made before they happen.


You don’t even need to have a specific problem in mind to start investigating poka-yoke opportunities. Why not run a poka-yoke audit in your small-business supply chain to identify the obvious mistakes that are made on a regular basis and poka-yoke them out of existence?


The Timeless Effectiveness of Lean Tools

Over the last couple of decades, larger organisations have focused the use of lean tools largely in the quest to reduce inventory. The trend today though is moving more toward a world in which lean inventory can introduce unacceptable risks in the supply chain.

For smaller businesses especially though, the use of lean tools need never go out of fashion. Techniques like the 5 Whys and poka-yoke can be used in so many ways to get rid of non-value-adding activity and make processes more cost-efficient.

At Dawson Consulting, our team will be happy to help your organisation identify and eliminate wasteful activity from your supply chain processes. To learn more about the strategic and tactical services we offer, contact us today at +61 418 445 341.