Manufacturing engineering

Steam locomotive and typewriter

Oct 25 2011

The steam locomotive and the typewriter

The first draft of my book  Working with Machines contained a chapter that was a post-mortem on two obsolete machines, which was cut on the grounds that, unlike all other chapters, it was not actionable for the reader.

Its abstract is as follows:

The steam locomotive and the typewriter are icons of the industrial age, and their parallel histories show different aspects of the human experience of working with machines. The steam locomotive is fondly remembered; the typewriter, all but forgotten except for the QWERTY keyboard. The steam engine participated in the development of every industrial economy, but the typewriter played no major role in Japan. The typewriter did not demonstrably improve the productivity or quality of office output, but was adopted only because of its image of modernity.

Locomotive driver was a prestigious position for a manual laborer, but typist never was. Compared to electrics and diesels, the steam locomotive had a cab that was exposed to the elements and to the heat of the firebox and therefore uncomfortable, difficult to operate, and dangerous. Yet engineers and firemen preferred it to the tedium and loneliness of modern locomotives. Automatic machines that require human attention only when they malfunction are also in airplanes and in manufacturing plants, challenging the job designer to keep the operator alert and used efficiently.

As the typewriter prints one keystroke at a time, typists were always busy with a single machine and determined both its productivity and output quality. Typists worked in comfortable places, but under pressure, and faced the long-term hazards of sedentary work. The typewriter’s main legacy is that a society can make a long-term investment in machines whose tangible benefits do not obviously exceed their costs.

Click here for a pdf file of the entire chapter.

By • History • 1 • Tags: , , ,

Dashboard assembly stations

Oct 23 2011

Why production matters

On LinkedIn Lean Business Process group, Ralph Bartelmann asked the following:

Is it really the matter to squeeze the last cent out of production ? In many environments production costs represent a minor part of the over all product cost. Following Pareto reasoning it seems more reasonable to work on other parts of the value stream like supplier developpement, product design etc. What is your opinion and experience ? What are the real challenges ?

Following is my answer:

It’s not about what production costs  but about what it does for the business. Improving production is about making is faster, better, safer, less tedious,… and cheaper.  It needs to be faster to make you more responsive, better so that production does not introduce defects that harm your reputation, safer and less tedious so that you can retain your work force and grow its skills.

If you improve on all these fronts, guess what? Your costs go down, and not only in production but in other parts of the value stream too, because they are not independent of production. For example, there is no point in trying to develop just-in-sequence suppliers unless you practice leveled-sequencing (a.k.a. Heijunka)  in your assembly line.

A manufacturing company ignoring production is an army ignoring combat on the grounds that more money is spent moving soldiers and keeping them supplied.

By • Management • 0 • Tags: , ,

To get to Dublin, you don't start from here

Oct 22 2011

Kaizen without prerequisites

Question from Pedro Burgos: You have an assembly line where ‘Standardized Work’ is not utilized. The operators have ‘work instructions’ and follow them. They do not miss steps. But there are differences between operators in how the work is performed in terms of sequence. All of them perform under takt time, some more than others. Due to ‘wastes’ of motion. You are asked to do a Kaizen to reduce inventory quantities and space. Inventory quantities on the production floor varies, some parts have 3 days of inventory, some have 2 days, some have 1 day (16 hours). The goal is a ‘kanban’ of 2 hours of inventory in the assembly line. Do you think is possible to do this Kaizen? (Discussion in the LinkedIn Global Lean & Six Sigma Network)

Your question reminds me of the old story about asking a farmer in the countryside of Ireland how to get to Dublin, and getting the answer that “you don’t start from here.” In fact, regardless of its current state, a production line can always be improved.

Looking further at the way you describe the challenge, however, several things disturb me. First, while Kaizen, meaning improvement, is always possible, “a Kaizen” seems to designate a Kaizen event, a project template which is not always appropriate. Second, your description suggests opportunities for productivity and quality improvement, but neither is stated as an objective.

A top-down mandate to use a particular method to pursue two goals like inventory and space reduction does not strike me as a recipe for success. Instead, someone needs to do the following:
1. Take a close look at this assembly line.
2. Identify improvement opportunities in all dimensions of its performance.
3. Select one or two to pursue in priority based on improvement potential, technical feasibility, and human feasibility.
4. Determine the project management approach based on content, rather than the other way around.

This approach is much more likely to achieve the desired inventory and space reductions, among other improvements, than just running a Kaizen event to pursue these objectives directly and exclusively.

By • Management • 1 • 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: , , , ,

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: , , , , ,

Feb 11 2011

Comparative advantage in the allocation of work among machines

Another NWLEAN post in response to Mike Thelen’s query on Laws of Nature, posted on 2/11/2011

On several occasions, I ran into the problem of allocating work among machines of different generations with overlapping capabilities. There were several products that could be processed to the same levels of quality in both the new and the old machines. The machines worked differently. For example, the old machines would process parts in batches while the new ones supported one-piece flow. But the resulting time per part was shorter on the new machines for all products. In other words, the new machines had a higher capacity for everything.

Given that the products were components going into the same assemblies, they were to be made in matching quantities per the assembly bill of materials and the demand was such that the plant had to make as many matching sets as possible. The question then is: how do you allocate the work among the machines?

When I first saw this problem, I thought it was unique, but, in fact, many machine shops keep multiple generations of machines on their floors and make parts in matching sets for their customers, and it is in fact quite common. The solution that maximizes the total output is to apply the law of comparative advantage from classical economics. Adapted to this context, it says that the key is the ratio of performance between the old and the new machines on each product. For example, if the new machine can do product X 30% faster than the old machine and product Y ten times faster, then the old machine is said to have a comparative advantage on product X, and you should run as much as possible of product X on the old machine.

It is a bit surprising at first, but easy to apply. What is more surprising is that so few plants do. The logic that is actually most commonly used is to load up the new machine with as much work as possible, on the grounds that it has a high depreciation and needs to “earn its keep.” What many managers have a difficult time coming to terms with is that what you paid for a machine and when you paid it is irrelevant when allocating work, because it is in the past and nothing you do will change it. You produce today with the machines you have, and the only thing that matters is what they can do, now and in the future.

The law of comparative advantage is taught in economics, not manufacturing or industrial engineering, and pertains to the benefits of free trade between countries, not work allocation among machines. The similarity is not obvious. This law is attributed to David Ricardo who published in 1817, based on an analysis of the production of wine and cloth in England and Portugal. Trade was free because, at the time, Portugal was under British occupation. Both wine and cloth were cheaper to produce in Portugal, but wine was much cheaper and cloth only slightly cheaper. England had therefore a comparative advantage on cloth, and the total output of wine and cloth was maximized by specializing England on cloth and Portugal on wine. You transplant that reasoning to your machine shop by mapping the countries to machines and costs to process times.

This simple approach works in a specific context. It is not general, but is of value because that context occurs in reality. The literature on operations research is full of more complicated ways to arrive at solutions in different situations. There is an article from IE Magazine in July, 2006 that I wrote about this entitled “Not-so-basic equipment: the pitfalls to avoid when allocating work among machines.” It used to be available on line for free on the magazine’s web site. Now you have to buy it on Amazon to download it.

By • Laws of nature • 0 • Tags: , ,

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