Business & Management The principles of Lean

WOO! Waiting. Overprocessing. Overproduction

The following are abridged and edited version of articles that first appeared in WHERE To Print, written by WTP columnist, Andrew Malson


There can be no value attributed to waiting. That sentence could be the start and end of this section.

The unit of measurement of waiting is time and while Time Management spurned an era of management thinking of its own, there are some simple points to consider when thinking of waiting waste to create value.

The elimination of waste is entirely possible in meetings and calls. Being on time (and prepared) eliminates wasted time, particularly important when the meeting has multiple attendees or callers; for every minute one attendee is late, all are late. I once took an extreme approach to prevent late arrivals by telling latecomers, in strong terms, to leave as soon as they arrived. Waste eliminated.

An exception to the rule of waiting

In terms of manufacturing, waiting is an indicator of problems at the core of the value stream. Production planning systems operate optimally when there is zero waiting but more often than not, a plant has higher capacity in one area (see below). Using quality and production data to analyse periods of waiting is time well invested. One site I controlled eliminated 50% of non-productive time by analysing the root cause of waiting for printing plates.

My point of this section is to highlight the need, again, for mindset change. If someone or something is not moving, then ask “why?”. OK, it might not be moving in the right direction but hopefully, the Spaghetti diagram and other techniques will identify that but when it’s not moving, it’s waiting and remember, “there can be no value attributed to waiting”.

Over production

By definition, overproduction is clearly wasteful and defies the underlying principle of Lean, but overproduction is an absolute necessity; an end product is impossible to create without ensuring that overproduction is contained within the process. We call this make ready or set up.

Make ready waste is inclusive to the point that it becomes part of the process. To some extent the waste is mitigated, as our estimators have (hopefully) calculated it into the cost of the job. For non-Lean practitioners, the conversation ends there but for people of a Lean mindset, everything that doesn’t add value is waste and waste has a cost, regardless of who “pays” for it.

overproduction creates bottlenecks and unsafe areas

Many years ago, I had the honour of escorting Masaaki Imai, the legendary creator of Kaizen and the founder of the Kaizen Institute, around a plant I controlled. As we walked around, I turned to the eminent Mr Imai and, with uncharacteristic hubris, stated,

“ Impressive, yes?”, which elicited the droll response of,

“Yes, very big warehouse”

Obviously, he was right. The work invested into making the presses efficient had resulted in over production; it had created a “push” system and created unnecessary bottlenecks. By looking at only one aspect of the process I had set up a wasteful, non-value production stream.

It would be churlish to argue that the production was a work in progress, even if that’s what I felt at the time, because I was not taking an holistic view of my production platform. Seeing the process, literally, as a stream, allows one to see the big picture and anticipate wasteful steps of over production.

The author at the finest moment of his career, just before being shot down in flames by the Sensei of Kaizen

A contradiction of over production is deliberate over production and, while it can have its benefits, it is fraught with RISK. I have found that it can only work within a very limited timeframe, yet I have known businesses pursuing this perilous model over years.

In a recent assignment I found that over production was the accepted norm, yet customers were complaining of unworkable, extended lead times. Changing the model to eliminate over production brought the plant to an acceptable performance level; identifying waste in the process created capacity, eased bottlenecks and improved flow.

If deliberate over production is your business model then it should be strictly controlled, short term and mitigated through mutual agreement.

Over processing

As Shingeo Shingo rightly surmised, “It’s only the last turn of the bolt that tightens it – the rest is just movement”. For this “O”, we could continue with, “and only the wasteful continue turning it”.

I have lost count of the number of businesses that have used proprietary ERP/MIS systems and then decided that their process needed something outside of that system. Performing the same or similar tasks in different locations is over processing and can lead to significant delays further down the value stream.

An excellent method to identify waste in pre-production is by using the Value Stream Mapping (VSM) tool. In essence, VSM identifies where your process is now (known as current state) and calculates what the ideal, or TAKT, time should be for each action in the operation (future state).

VSM provides a detailed understanding of the entire flow of the value stream, although efforts at improving TAKT will be more efficient if focussed at the beginning of the process and then reassessing after each improvement. In Lean terms we refer to this as PDCA. Plan, Do, Check, Act.

T = \frac{T_{a}}{D}

Over processing in the production cycle takes different forms. Over processing because of the incumbent methodology is often overlooked, as it is an accepted part of how the system works ( the “we’ve always done it like that” philosophy, as espoused by the alumni of Luddite University). Frequent use of the “why” technique will provide questions, if not necessarily answers, to whether the current process is the most effective.

This also applies to quality and the frequency and stoppages for inspections. Every employee has a direct responsibility for the quality of the product that leaves their site but quality needs to improve the process flow, not suppress or stop it.

Analysing inspection points and asking “why are you doing that?” is an entirely appropriate method of determining over processing, on the basis that if the inspection isn’t justified, it is waste. If, by asking further “why’s”, the answer is that there was a problem; there’s a problem, a waste problem. 

If you don’t agree with me, go take a look through your production operation today and ask the “why are you..?” question and see if that inspection is still relevant. 

© Andrew Malson July 2020

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