-December 2005-  

       are your manufacturing processes controlling YOU?

Myth or Mantra?  Is Six Sigma for Canmakers and Suppliers?

Awareness that Six Sigma techniques can be used for managing processes is widespread, but a complete understanding of their value less so. What can they offer CANMAKERS and SUPPLIERS?

We are likely to have been exposed to Six Sigma to varying degrees, or at least heard about it within the canmaking industry.  It is particularly relevant, given that our industry produces a huge volume of product worldwide and provides us one of the most data-rich production environments in the world.  

But does this really matter? While many people, especially those specialists in the Six Sigma field, will answer with a resounding “no”, in fact it is important, because it enables us to quickly and efficiently gather enough data for all forms of statistical analysis.

So, what exactly is Six Sigma? Simply put, if you manufacture anything you produce defects, pure and simple, there’s no getting around it. The quantity of these defects and their prevention is the focus of all Six Sigma efforts. 

In manufacturing we use targets and work within tolerances; these are the desired outcomes of the process. Measuring the variables of the product we obtain clusters of data surrounding those targets.  Statistical law dictates that there will be mean figures (averages) and variance from them. These are measured in terms of ‘sigma’, or standard deviation, a statistically-calculated value. Sigma is simply a measure of the variation inherent in any process.

The definition of a Six Sigma process is the ability to have allowable tolerances such that they are located six standard deviations (Six Sigma) to either side of the target (or mean).  A simple explanation is that at that point the process produces 3.4 defects per million opportunities.   

Is there anything sacred about the Six?  No, six is today’s accepted standard within quality circles, but is rather arbitrary, as it may not be applicable (or even achievable) in some industries.

 

Canmakers and Six Sigma

Some canmakers have undertaken formal Six Sigma programs and with good reason. The competitive base is shrinking and other packaging types continue to gnaw at the metal packaging market, making striving toward operational excellence that much more desirable. Also, as in all businesses, profitability will eventually be the exclusive domain of the best-in-class, given worldwide competitive pressures, more discriminating customers, and the use of fewer resources. 

In a highly-productive process environment, such as canmaking, Six Sigma enables us to focus on the elimination of guesswork, trial & error, and just plain luck. If you are not employing statistical methods in controlling processes, you are not performing process control, but some other system that may indeed be based upon “pseudo-science.” 

A visit to this year’s MetPack convention highlighted that one of the major concentrations in metal packaging today is on inspection, and most often 100 percent at that. Is this good or bad?  Neither, really, as 100 percent inspection eliminates the chance, in theory at least, of shipping bad product to the customer. However, unless the data is being captured and analyzed to enable the prediction of problems that have yet to occur, this inspection is reactive, so it is actually measuring process history and focusing on past production (even if that past is only measured in milliseconds).

In contrast, Six Sigma methods are proactive, in that they focus on predicting and preventing defects, and in effect focusing upon future production. The inspection systems that today’s canmakers are employing contain the potential to capture a much-needed wealth of information. The result could be a set of systems designed not only to ensure that defective cans are not shipped, but to also predict if they will be produced at all, and halt their manufacture before it ever happens.

 

Six Sigma, Canmakers and Suppliers

So how does Six Sigma influence the relationship between canmakers and their suppliers? Today’s canmakers call for various levels of ‘efficiency’ from their suppliers; usually a ratio of the number of acceptable cans produced to the number of cans theoretically expected. Currently ‘efficiencies’ above 90 percent are expected. But this requirement is wrong. Why?

First, this ratio is actually a measure of productivity, not efficiency: the actual number of cans produced versus what was expected. Therefore, is there an ‘efficiency’ to be measured? Yes, but it is not as simple as just the productivity ratio, 

True efficiency actually consists of three broad measures: machine (or line) uptime, productivity, and especially quality, with each quite interrelated.

Machine (or line) uptime is the easiest to quantify. It is most often driven by machine (or line) design (the major contributor)plus maintenance practices, settings, repairs, and line control, to name a few. 

Productivity, conversely, is a bit more complicated. Each machine in a canmaking line receives an input quantity, such as coil, cups, trimmed cans, and so on. However, these same machines receive also quality, especially in terms of their variations. It is the combination of the input quantity, but most importantly quality, that will affect the productivity of a machine or process. There are scores of quality attributes inherent in any canmaking line, given the many processes cans undergo, along with the many design requirements they possess. 

But what now about quality?  The machines in a canmaking line not only produce quantities of cans, but also are responsible for variations in quality. These quality variations cascade throughout the line, sometimes exhibiting statistical ‘balance’ but most often wreaking process chaos. This is where Six Sigma methods shine, as they are directed at first quantifying process variation (which is the most difficult part of the task) and then providing statistical means to put the process predictably on target and with minimum variation, versus ‘waiting to see’ how the quality will vary (and eventually drift out of specification). 

Six Sigma, when applied to current processes, examines the effects of a machine or line that has already been designed and is running. In contrast, Design for Six Sigma, an extension of Six Sigma, focuses upon creating machines or lines that will exhibit operational excellence right ‘out of the box’. 

The program is designed to eliminate the constant ‘debugging’ of machines or lines (or materials for that matter) that is so typical today and -- for suppliers in particular -- the nagging warranty that sometimes emanates from new product development; not to mention the grief experienced by canmakers. 

Suppliers that have earned great reputations as those that truly stand behind their products when they fail should actually be concentrating upon preventing the problems in the first place. Remember that the best firefighters are sometimes also the arsonists.

So, what is the point of Six Sigma? In canmaking, as in all manufacturing industries, everyone is simultaneously a supplier and a customer. Machinery and materials suppliers service the canmakers, who in turn are serviced by second-tier suppliers. The canmakers in turn service the fillers. The point of Six Sigma is to ensure that measurable quality finds its way through this supply chain. We are living in a time where ‘goalpost’ specifications (plus or minus tolerances) are both archaic, and quite frankly, useless. All companies in our supply chain should be supplying measurable quality to their customers and expecting the same from their suppliers.

 

Why do companies fail at Six Sigma?

Companies actually fail at Six Sigma efforts, and often quite miserably. Why? There are several underlying (and very common) reasons: 

1. Six Sigma is not applicable to that company.  This is sometimes the case; however, again given the extensively data-rich nature of our industry, we do not fall into this category.

2. Six Sigma is indeed applicable, but the company does not see that need. This phenomenon produces the ‘programme-du-jour’ that quickly fades into oblivion. Perhaps the company has been forced by a corporate owner to take on a Six Sigma program, but merely goes through the motions.

3. Lack of cultural change. Six Sigma requires a different way of approaching problems.  If this cannot be communicated throughout the organization, failure is almost always imminent.

4. Lack of accountability. Six Sigma trainees fade into the corporate background, shrouded in mystery, with precious few people knowing what ‘exactly it is they do’.

5. Top management disinterest.  If top management does not support such a program, it is fairly obvious why it would fail, but that is not what we are considering here. What is worse is top management’s lack of familiarity with Six Sigma procedures, measures, and nomenclature. How can a company officer lead a Six Sigma based organization without at least some familiarity with the ‘deliverables’ of the program?

6. Firefighting. Companies sometimes cannot devote resources to a Six Sigma program because those resources are too busy ‘firefighting’.  It is ironic that the very goal of Six Sigma is to eliminate firefighting.

7. Certification ‘mania’. Black belts, green belts, yellow belts, master black belts: will it never end? Companies often focus on ‘belting’ as many people as possible, only to see those people eventually go back to attend to their ‘real jobs’.  This often results in excessive training of an inappropriately short duration, coupled with extensive misuse of statistical software packages. Having such software does not make one a statistician.

8. Misplaced concentration. This may also be couched as ‘tool mania’, or how many Six Sigma statistical “tools” are being employed. The concentration should never be upon tools, but upon results.

9. "To thine own self be true..."  Some companies have actually convinced themselves they operate at some particular Sigma level.  However, were one to question an executive within such a company as to the significance of such a measure, there is a good chance that a blank stare would ensue.

10. Unnecessarily taking on an entire Six Sigma "program."  Some companies are convinced - quite often by consultants - that a full-blown Six Sigma effort is the only way for that company to become competitive.  While there is some merit in this, many companies will fail due to the reasons listed above, among countless others.  It is often in a company's best interest to bite off the Six Sigma methodologies in manageable pieces, concentrating initially on cursory training and allowing Six Sigma consultants to come in and do what they do best: solve problems.