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.
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)