Continuous improvement

River Rouge Coke Ovens 1946-1976

Nov 8 2011

Factory life with and without Kaizen

In Kaizen, Masaaki Imai describes Japanese executives returning in the 1970s to American plants they had visited thirty years before and being struck by the absence of change: they saw the same production lines with the same equipment operated the same way. This started me looking for photographic evidence. Overall, pickings were slim, but I did find the above pictures of the same coke oven at the Ford River Rouge plant shot in 1946 and 1976.

If there is Kaizen activity in a factory, how does it change the work life of employees at all levels? The following chart compares the breakdowns of their use of time, with and without Kaizen:


In a plant without Kaizen, operators and supervisors are fully occupied with routine daily tasks: production for the operators, expediting parts, enforcing discipline, and record keeping for supervisors. Only middle managers and executives spend a fraction of their time on projects involving capacity changes, new production lines or new technology. Nobody works on incremental improvements to the way the work is done today.

By contrast, Kaizen involves employees at all levels  in such improvement activities to different degrees. Between improvement and daily routine, the boundary is sharp;  between improvement and innovation, fuzzy. Over time, the cumulative effect of incremental improvement is radical change by itself. In addition, the skills acquired and the lessons learned from incremental improvements are incorporated into new line or plant design projects. In some Japanese auto parts plants, I remember seeing automatic lines side-by-side, where one used old machines that had been gradually retrofitted with devices that reduced the need for human intervention, while the other one had been built from scratch with new machines to be automatic. The Kaizen work done to implement the former was essential to the success of the latter.

By • Management, Technology • 10 • Tags: , , , ,

Continuous improvement from bolts to clamps

Oct 19 2011

The Role of Technology in Continuous Improvement

In an article on this topic in Industry Week today, Ralph Keller asserts that Continuous Improvement is focused on business processes rather than technology.

However, if you wrap tinfoil around the feet of a welding fixture to make it easier to clean, replace bolts with clamps on a machine to reduce setup time, or mount a hand tool on the machine on which it is used, it usually counts as Continuous Improvement but involves technical changes to work that I don’t think anyone would describe as business processes.

Yes, Continuous Improvement is done without expensive technology, but it does involve cheap technology.

Ralph Keller also reminds us that Continuous Improvement is not “rocket science,” which implies that it is easier. I agree that it is different, but not easier. I don’t know any rocket scientist with the skills to facilitate Continuous Improvement.

By • Management • 0 • Tags: , , , ,

Jun 14 2011

Management Whack-a-Mole and the Value of Lean

On 5/24/2011, NWLEAN moderator Bill Kluck launched the richest, most vigorous debate in the 13-year history of that forum by asking members whether they were cost cutters or capacity enhancers. Over the following three weeks, 29 authors posted 68 spirited, yet courteous messages accessible from NWLEAN to anyone with a Yahoo! ID.  The contributors included several well-known authors and some of my favorite sparring partners. In alphabetical order, they were  Dan Barch, William Bowman, Robert Byrd, Abhijit Deshpande, Mark Graban, Jim Harrington, Jonathan Harrison, Rob Herhold, Blair Hogg, Gangadhar Joshi, Bill Kluck, Joachim Knuf, Ed Larmore, Paul Layton, Ted Mayeshiba, Jim McKechnie, Larry Miller, Joe Murli, John Nelson, Stephen P. O’Brien, Anthony Reardon, Tom Robinson, Sunita Sangra, Dale Savage, Patrick D. Smith, Tom Stogsdill, Mike Thelen, Chuck Woods, plus a few others who did not use their real names.

The message that started the thread was as follows:

“It seems more and more (especially in this recession!) that lean professionals fall into 2 camps:
– Cost cutters
– Capacity enhancers
There are some out there that are saying that you HAVE to cut costs, or you’re not getting lean.
There are others that say lean is about improving capacity, so you can enhance the customer experience.
Which are you, and why? Is this driven by the top of your organization, people who may not understand what lean is? Do we risk becoming cost cutters, or smoke-and-mirror guys?
Just askin’!

Bill”

Although I didn’t participate initially, it was clear to me that the effect of a successful Lean implementation was limited neither to cost cutting nor to capacity enhancement. Instead, I see Lean as the pursuit of concurrent improvement in all dimensions of manufacturing performance, but I had already shared my thoughts on this matter in Lean as the End of Management Whack-a-Mole. Management Whack-a-Mole is the game illustrated in Figure 1, in which managers  boost performance in one dimension at the expense of the others, shifting focus every few months without ever achieving a genuine overall improvement.

Figure 1. Management Whack-a-Mole

Several of the early posts, however, prompted me to  jump into the fray and respond on a variety of topics, initially as follows:

  1. People trained in Finance and Management Accounting have had their shot at running US Manufacturing from the 1950s to the 1970s, with outcomes that should make them modest about the value of their approaches.
  2. Companies that have grown through Lean include Toyota since 1950, Wiremold from 1991 to 2000, and many others that are not publicized. A successful Lean effort helps Sales in specific ways, as, for example, when more flexibility enables Manufacturing to accept a sample order for a new component by a customer, who then designs it into his own products and becomes a major OEM.
  3. Cost reductions are a by-product of Lean but not its primary purpose. Manufacturing is a competitive sport, and Lean a strategy that makes you a stronger player, and not just right now but in the long run as well. When you hire a top coach for a sports team it’s not to cut costs but to win games.
  4. ROI is just one ratio, invented at DuPont 100 years ago to report in a common form the activities of multiple business units. There is nothing magic about it, and, by itself, it certainly does not give a complete picture of the health of a business, as even finance people recognize.

This caused further exchanges with Robert Byrd, who wrote: “…The most basic concept is Profit = Price – Cost. The market dictates price, so we have the best leverage for maximizing profit through controlling our cost structure…”  My response:

Is this always true? What about situations in which time to market is of the essence? I remember a client that was introducing a new frozen food product. On one of our visits they had us taste the R&D prototype, which was delicious. Three months later, they had a jury-rigged production line making 900 units/minute. The line left much to be desired, but we could not argue with their focus on getting the product to market. During all that time, their focus was not on getting it done cheaply but on getting it done at all. Then they could go back and improve the line.

He also wrote: “…Which is best accomplished through the elimination of waste and problem solving…”  My response:

This is the key point. We have yet to encounter a manufacturing or service organization in which the details of how work is being done contains no improvement opportunity, and this is what most managers simply do not believe. They are trained to think in terms of “big pictures,” and look for cost cutting opportunities like eliminating entire departments or reducing every department’s budget by 5%.

And finally: “If the aim is only to increase profit by reducing cost, without focus to grow the business, then the culture will never take root and only a short-term improvement will be realized. Or the company will never achieve it’s true potential.”

Your point does not fit in a 30-sec sound-bite or tag line. Good managers are able to monitor all aspects of performance at the same time, from growth to costs. But communication is tricky. For example, if you showcase ” Profit = Price – Cost,” what behaviors do you expect to stimulate, other than cost cutting?

In his second response, he added: “However, what was their business objective once they focused on improvement? I would venture to guess that it was focused on cost reduction.” My response:

I don’t recall them mentioning cost reduction explicitly. When the line first started, about 20% of the units were defective, and that was a focus of concern. Of course, quality improvements reduce costs as a side effect, but they also have other effects: quality problems have an impact on customer perceptions of the product because of variability among the units that are not defective.

In their other production lines, improvement was driven by marketing concerns. This was in Europe, and, in spite of the existence of the EU, frozen food packages had a different sizes by country, in addition to having labels in different languages. Based in Italy, they pursued quick changeovers in package sizes in order to be able to export to Germany, France, the UK, etc.

Their Lean program fit within their business strategy, but it is a stretch to say that this strategy was centered on cost reduction.

By • Management • 10 • Tags: , , ,

Mar 3 2011

A factory can always be improved

Based on an NWLEAN post entitled: Laws of Nature – Pareto efficiency and Pareto improvements, from 3/3/2011 

In manufacturing, Italian economist Vilfredo Pareto is mostly known for the Pareto diagrams and the 80/20 law, but  in economics, he is also known for the unrelated concept of Pareto efficiency, or Pareto optimality, which is also relevant to Lean. A basic tenet of Lean is that a factory can always be improved, and that, once you have achieved any level of performance, it is just the starting point for the next round of improvement. Perfection is something you never achieve but always pursue and, if you dig deep enough, you always find opportunities. This is the vocabulary you use when discussing the matter with fellow production people. If, however, you are taking college courses on the side, you might score more points with your instructor by saying, as an empirical law of nature, that a business system is never Pareto-efficient. It means the same thing, but our problem is that this way of thinking is taught neither in Engineering nor in Business school, and that few managers practice it.

A system is Pareto-efficient if you cannot improve any aspect of its performance without making something else worse. Managers who believe their factories to be Pareto-efficient think, for example, that you cannot improve quality without lengthening lead times and increasing costs, which is exactly what Lean does. In fact, eliminating waste is synonymous with making improvements in some dimensions of performance without degrading anything else, or taking advantage of the lack of Pareto-efficiency in the plant.

When we say that a factory can always be improved it is a postulate, an assumption you start from when you walk through the gates. The overwhelming empirical evidence is that, if you make that assumption, you find improvement opportunities. Obviously, if you don’t make that assumption, you won’t find any, because you won’t be trying.

This is not a minor issue. Writing in the Harvard Business Review back in 1991 about Activity-Based Costing, Robert Kaplan stated that all the possible shop floor improvements had already been made over the previous 50 years. He was teaching his MBA students that factories were Pareto-efficient and that it was therefore pointless to try and improve them. They would do better to focus on financial engineering and outsource production.

The idea that improving factories is futile and a distraction from more “strategic” pursuits dies hard. It is expressed repeatedly in a variety of ways. The diminishing returns argument is that, as you keep reaching for fruits that hang ever higher, the effort requires starts being excessive with respect to the benefits, but there are two things to consider:

  • As you make improvements, you enhance not only performance but your own skills as well, so that some of what was out of reach before no longer is.
  • Competition is constantly raising the bar. If your competitors keep improving and you don’t, you lose.

Another argument is that the focus on waste elimination discourages activities like R&D that do not have an immediate impact on sales. The improvement effort, however,  isn’t about what we do but how we do it. Nobody in his right mind would call R&D waste, even on projects that fail. Waste in R&D comes in the form of researchers waiting for test equipment, sitting through badly organized meetings, or filling out administrative paperwork.

In manufacturing itself, some see the pursuit of improvement as a deterrent to investment in new technology. While it is clear that the improvement mindset does not lead to solving every problem by buying new machines,  the  practitioners of continuous improvement are in fact better informed, savvier buyers of new technology. On one side of the shop floor, you see a cell with old machines on which incremental improvements over several years have reduced staffing requirements from 5 operators to 1. On the other side of the aisle, you see a brand new, fully automatic line with a design that incorporates the lessons learned on the old one.

Others have argued that a society that pursues improvement will be slower to develop and adopt new, disruptive technology. But does the machinist improving a fixture deter the founder of the next Facebook? There is no connection. If the machinist were not making improvements, his creativity would most likely be untapped. And his improvement work does not siphon off the venture capital needed for disruptive technology.

By • Laws of nature • 14 • Tags: , , , , ,

Little's Law concept

Jan 13 2011

Lead times, work sampling, and Little’s Law

On 1/11/2011, Michael Thelen asked in the NWLEAN forum about “laws of nature” as they related to Lean. This is based on one of my answers. 

Lead time is a key performance indicator of manufacturing operations, but how do you measure it? It is not a quantity that you can directly observe by walking through a plant. To measure it directly you need to retrieve start and finish timestamps from historical data, assuming they are available and accurate. Or you could put tracers on a sample of parts, which means that it would take you at least six weeks to measure a six-week lead time. In most plants, however, a quick and rough estimate is more useful than a precise one that takes extensive time and effort to achieve.

That is where work sampling and Little’s Law come in handy. The key idea of work sampling, which the Wikipedia article fails to make clear, is that lets you infer a breakdown of each entity’s status over time from snapshots of the status of multiple identical entities. If, every time you go to the shop floor, you see 2 out  of 10 operators walking the aisle, you infer that, on the average, each operator spends 20% of the time walking the aisle.

There are obviously necessary conditions for such an inference to be valid. For example, you want to take snapshots during normal operations, not during startup orshutdown, and the group you are measuring must be homogeneous: if it is comprised of two materials handlers and eight production operators, the 20% average is not interesting, even if it is accurate. Work sampling is usually described as applied to people, but the same logic is applicable to machines and to work pieces, and that is what makes it possible to infer lead times from snapshots of inventory and throughput rates.

On the shop floor, you can count parts, bins or pallets, and observe the pace at which they are being consumed. Let us assume we are in the context shown in Figure 1, and want to estimate how long we take to turn a blank into a finished good.


Figure 1. Context of Little’s Law

Little’s Law, then, says that on the average,  in steady state, within one process or process segment,

Inventory = Lead time X Throughput

The reason this is true is best explained graphically, as in Figure 2, in the simple case of constant throughput and lead time. The cumulative count of blanks in is a straight line going up over time, and so is the count of finished goods out, offset by the lead time.  The vertical distance between the curves is the number of blanks that have come in but not yet made it out as products, and represents therefore the inventory. The slope of each curve is the throughput, and it is clearly the ratio of the inventory to the lead time.

Figure 2. Little’s Law with constant throughput and lead time

What is interesting about Little’s Law is that it remains valid about averages when both rates of arrivals of blanks and departures of finished goods are allowed to fluctuate randomly about an average. This is probably the best known and most useful general result of queueing theory.

Since we can count inventory and measure throughput, we can infer average lead times from just this data. One snapshot will not give you an accurate estimate, but it is still considerably easier to take a few snapshots of a production line to get a more accurate estimate than it is to research history. The point is to get close to an answer that would take much longer to get if you actually had to be accurate.

By • Laws of nature • 2 • Tags: , , , , ,

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