The blurring definition of Lean waste in a 4.0 world – Part 1 of 2 – Additive Manufacturing

Until recently in the Lean community, the definition of waste was “simple”: waste is any activity consuming resources without producing value for the customer. In this definition time can be  considered a resource and “customer” is extended to anyone beneficiary of the outcome, like a patient in a hospital getting faster and better care.

Focusing on industrial operations, nowadays with new technologies which define Industry 4.0smart manufacturing or the Digital Revolution, the definition of waste may be blurring. Let me explain.

For tens of years machining was about cutting away excess material from a chunk of metal or raw material in order to get a part which may continue its journey of transformations along an industrial process, with more or less other transformation steps like milling, lathing, sub assembly, surface treatment, quality control, tests, finishing, etc.

Cutting away excess material was counted among the value-added steps because it transforms a piece of raw material (useless to customer in that state) into something with higher value, that eventually will end up in the hands of the customer willing to pay all sorts transformations in order to get the final parts or product he/she ordered. There was hardly any alternative to produce the desired part or product.

But now, in the age of Additive Manufacturing, a part can be “printed” using the just needed raw material, without the need of wasting a significant part of it for cutting away (a kind of carving out) in traditional machining.

These savings in raw material can be very significant, both in volume and value, especially with high grade metals like titanium used in aerospace industry. Blank parts are “printed”  using the just required quantity of this high grade metal, with the minimum of excess thickness in order to be machined with the desired precision and surface condition afterwards. In this case, the very expensive high grade titanium is used wisely with significant savings compared to the traditional method.

When facing the choice between traditional machining and additive manufacturing, the first method can no longer be seen as value-adding because of the proportion of high-grade metal which is wasted to shavings, compared to the latter method which is more effective with regard to the use of raw material.

Especially, when environmental concerns come into play, the most effective method should be preferred as the waste of high grade raw material can usually only be recycled in lower grade material and products. These shavings and recycling have then to be considered as waste.

Therefore the definitions of waste and value-adding are blurring as new ways to achieve similar results become available.

Some may consider this is just an evolution of technologies and Lean will naturally adapt to the new circumstances, a way of thinking I share, with some cautious reservations though.

It can be puzzling to have some operations being considered value-adding in one thinking way (3.0 or traditional manufacturing) and waste in another system (4.0). This is why I ask myself is there is a need to clarify the way of thinking and to call this extension of Lean “Lean 4.0” or if Lean does not need any versioning / numbering system at all?

>Proceed to part 2/2 (soon)

About the author, Chris HOHMANN

About the author, Chris HOHMANN

View Christian HOHMANN's profile on LinkedIn

2 thoughts on “The blurring definition of Lean waste in a 4.0 world – Part 1 of 2 – Additive Manufacturing

  1. Hi Chris,

    Technically speaking… “Machining” – as defined above – is a practice that has been performed by human beings and their predecessors for many, many thousands of years; beginning with stone on stone. Needless to say, that practice has evolved along with the various species utilizing it. From stone to soft metals to hard metals to sophisticated alloys and composite materials, the practice and materials it is applied against continues to evolve. As you noted above, today’s most advanced “machining” techniques fall into two broad categories… ADDITIVE and SUBTRACTIVE. And the most sophisticated tools and techniques employ a combination of both under the control of a computer program… NOT a human being.

    It’s the advent of these sorts of capabilities on the manufacturing front that open the door to new types of production processes. And, thus far, we’ve only scratched the surface when it comes to leverage them to achieve not only vastly superior product designs, but also the most efficient and effective manufacturing processes. Accordingly, not only will the “MACHINING” technologies have to be further evolved and mastered, but so to will product design principles and practices such that they fully leverage the capabilities that exist on the manufacturing/production side of the equation. Ergo, unless these two bodies of knowledge and practice are more tightly integrated, it will be IMPOSSIBLE to reduce the amount of WASTE that is being generated in the overall NPPD/I and standardized production processes.

    [Note: It has long been known that there is a combined efficiency and effectiveness penalty associated with having to remove material in order to get to a desired final shape. The more material that needs to be removed, the greater the penalty. In light of this realization, there has been – for quite some time now – the practice of NEAR-NET SHAPE CASTING/FORMING that greatly reduces the amount of material that needs to be removed to make the final entity. In fact, one US-based start-up that I’m aware of has virtually done away with the need for any machining. In their proprietary process for metal deposition, they can create a “finished” product – of any shape – without any cutting… just by adding.

    But before this new approach takes hold and finds usage across a wide range of applications, it’s important to now that ADDITIVE MANUFACTURING by itself is often NOT SUFFICIENT to deliver FINAL FORM tolerances and surface finishes that are required by many parts being used in a wide range of applications. Accordingly, the COMBINED USE of both ADDITIVE and SUBTRACTIVE methods is considered essential. And only one company I’m aware of (which is located in GERMANY) has mastered the combination in single machine. And needless to say… IT’S AN EXPENSIVE PIECE OF EQUIPMENT! Therefore, it’s not ready for prime time in every MOM and POP manufacturing operation. I’d love to see what TITAN GILROY could do with it.


  2. Hi,
    I think this particular case should not be a problem, both steps are value adding therefore not a waste. The difference is that one step is more wasteful than the other but this is a completely different piece of cake.

    Just imagine you had a process with traditional machining and you had a DMAIC that improved the step in a way that you need to shave off 20% less than previously. Would this make the original unimproved process step a waste? Surely not.

    Kind regards


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