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Six Sigma’s Seven Deadly Sins

by James P. Zimmerman and Dr. Jamie Weiss

Quality and productivity initiatives have come and gone over the past few decades: quality circles, statistical process control, total quality management, customer focus, business process reengineering, Baldridge protocol diagnostics, enterprise-wide resource planning, high-performance work teams, self-directed work teams, systems thinking, and lean manufacturing. Most have been sound in theory but shaky in implementation, never quite delivering on their promises—at least not consistently and over the long run.

One of the more lasting of the many initiatives has been Six Sigma, which General Electric has defined as a breakthrough for “consistently developing and delivering near-perfect products and services, based on looking ‘outside-in.’” Organizations such as GE, Motorola, Allied Signal/Honeywell, Federal Express, and Johnson & Johnson have achieved stellar results with Six Sigma.

But in many organizations there is real danger of having Six Sigma wind up, like many of its predecessors, in the dustbin of history. In fact, an Aviation Week magazine survey of major aerospace companies concluded that, “. . . less than 50% of the survey respondents expressed satisfaction with results from their Six Sigma projects; nearly 30% were dissatisfied and another 20% or so were only somewhat satisfied.”[1]

In our work with manufacturing and service organizations, both in the U.S. and abroad, we have seen many examples of Six Sigma interventions that have not delivered on expectations. Inevitably, these interventions have fallen victim to the following seven factors or “sins,” any one of which can turn all the initial rah-rah for Six Sigma into a desire to look for yet another silver bullet.

The Seven Sins of Six Sigma

1. Inadequate Information

In one organization with which we worked, a warranty-claims information system automatically archived information once the claim had aged for six months. Unfortunately, the information remained buried in the IT Department, and very few users of the system even knew it existed. It wasn’t until we were working with the company’s engineers on three parallel problem investigations that we detected a pattern: Each claim had spiked out of control exactly six months previously. Only then did the engineers go to the IT Department, where they found the critical historical information needed to isolate and correct the problems. As the engineering manager put it, “No wonder it took us so long to resolve warranty problems!”

Here’s a related information transgression: measurementitis. Today’s volume of quantifiable information is overwhelming, and organizations often succumb to the tendency to gather and analyze all of it. Successful Six Sigma initiatives include streamlined information-gathering and retrieval systems that avoid information overload and limit analysis to relevant, accurate data.

Information inadequacy can also stem from faulty assumptions, especially those related to product cost and value. For example, standard costing approaches typically underestimate the cost of low-volume products and overcost high-volume ones. This can dramatically skew Six Sigma project selection and results documentation.

We worked with a company that produces bulbs for automobile headlights. Each of the company’s customers had specified a different design for its bulbs, and the manufacturer had complied. When we reviewed the true costs of the company’s product “portfolio,” executives were amazed to learn that hundreds of SKUs were actually being produced at a loss. The standard costing approach they had been using had actually blurred everyone’s understanding of product profitability.

To remedy the situation, the company went to each customer and asked if it could use a standard bulb without compromising performance. Result: a better-designed, higher-quality product, manufactured at less cost and with less complexity.

The best way we know to ensure that you have adequate information on which to base your Six Sigma initiatives is to use a consistent set of questions to gather, sort, organize, and analyze information. One high-tech manufacturer trained all of its customer-support reps to ask the same set of questions, designed to obtain a tighter description of the “what, where, when, and extent” of a problem, and to look for unique features and key changes each time a problem arose. By reducing the variation in how information was captured at the outset of a call, the average time to resolve customer problems was slashed by 58 percent.

2. Selecting the Wrong Projects for Six Sigma

A medium-sized IT-services firm moved to implement Six Sigma in order to achieve operational efficiencies. When, nine months into the effort, projects were piling up with no sign of progress, management finally decided to step back, formulate an overall strategy, and then design a project-selection process. In the course of the effort, they discovered that over 60 percent of their existing Six Sigma projects had no impact on high-priority product or market segments. They were doing things right, but they were doing the wrong things!

Selecting inappropriate Six Sigma projects is widespread. As the Aviation Week survey cited earlier observed, “60% of the companies in the survey selected opportunities for improvement on an ad hoc basis or within specific functions, such as the shop floor or the purchasing department. Very few (31%) rely on a portfolio approach. Companies that do manage the Six Sigma pipeline using portfolio techniques tend to see better results.” [2]

Some reasons that organizations select the wrong projects for Six Sigma:

  • Picking easy, operational wins, as opposed to zeroing in on projects that advance the business strategy.A medical products client of ours had one Black Belt team working on a yield problem in one of their product lines. Over the course of a few months, the team was able to institute improvements leading to a 22 percent increase in production. Congratulations mounted until someone in Accounting mentioned that, while the degree of the improvement was impressive, its impact was not. The product was only manufactured for two days a year, and a 22 percent improvement amounted to a little less than the cash the accountant happened to have in his pocket! Organizations need a set of strategic criteria against which potential Six Sigma projects can be evaluated, and projects that don’t meet these shouldn’t even be considered.
  • Sidestepping the “right” Six Sigma projects because they are perceived as too difficult, too contentious, or too tough to measure. In some cases, projects are overlooked because they entail challenging or phasing out “cash cows” or other old-favorite products or processes that are past their prime. Many companies begin their Six Sigma programs by going after “low-hanging fruit” in order to build success and momentum. These organizations need to ask: “What message does this send?” and “How will we transition to attacking the few critical issues that will determine the fate of our business?”
  • Attempting to solve a marketing problem with a manufacturing solution. Take this test: Generate a scatter-plot of all your products or services in the two dimensions of Volume and Margin (Figure 1).

Chances are, the products and processes that fall into the High-Margin/Low- Volume Quadrant would not be good candidates for Six Sigma improvement. Given their high margin, significant efficiency has already been achieved. The issues here are obviously not manufacturing ones; they call for improved marketing, and traditional Six Sigma can’t help.

3. Creating Solution-Caused Problems

In one large pharmaceutical operation, a substance was ground to a powder before being shipped to a sister plant and blended into capsules. The grinding machine kept jamming, so operators decided to reset it for a finer granulation. This solution worked extremely well: The fine powder didn’t stick or cake up like the thicker grind. The machine stopped jamming, and everyone was happy. That is, until they got a call from the sister plant. It seems that the 20 drums of powder they shipped after resetting the machine had turned into cement and could only be removed with a hammer and chisel.

Four of the most powerful words in the language of implementation are these: “What could go wrong?” Forget to ask this question when implementing a solution or making an improvement, and you’re bound to run into difficulties. Every implementation plan should include an analysis of potential problems, their likely causes, and preventive and contingent actions. Involve customers and suppliers in the analysis and focus your team’s efforts on the high-threat deal breakers.

4. Serving the Wrong Customer

A basic element of all Six Sigma projects involves listening to the “voice of the customer.” Yet, in practice this focus is often perverted or diluted. A survey conducted by Greenwich Associates concluded that:

Strangely absent from most user responses was any mention of the customer. When asked on an unaided basis to define a successful project, only three out of the 13 companies mentioned customers as critical success factors—despite the first rule of Six Sigma, listening to the Voice of the Customer. [3]

One way in which organizations turn a deaf ear to customers is by confusing the voice of the customer with the voice of accounting. Consider the many companies that have used Six Sigma methodology to improve customer support, especially in help-desk environments. The “improvements” they’ve made—seven-tier voice-mail systems, confusing help screens, and downright useless Web sites—may be cost effective, but they deflect the customer’s voice and try his or her patience.

Over-reliance on benchmarking can also distort the customer’s voice. Sure, it is advisable to be aware of the competition’s best practices and innovations. But it’s important to remember that their strategy may be quite different from yours, their problems unique to them, their solutions more fitted to their own culture or customer base. The voice you should be listening to is that of your customer, not theirs.

A tier-two auto-interior supplier that had experienced quality problems was struggling to retain the business of its major customers, several of whom were threatening to take their business to a competitor. In an effort to improve customer satisfaction, the plant manager formed Six Sigma teams around top-priority process concerns, making sure that customers were actively involved in the effort. As each project was completed, team presentations were made to the customers’ leadership teams articulating the cause(s) of the problems, intended solutions, implementation plans, control methodologies, etc. The bottom line: All of the company’s major customers stayed with it, and revenues increased in each of the subsequent three years. A customer voice well heard!

5. Leaping to the Fix

Far too many Six Sigma teams end up brainstorming improvement ideas prior to fully understanding the cause of poor process or product performance. When attempting to correct problems within a work process, most teams immediately leap into action. While this is understandable, given the pressure to get things up and running, in the long run it’s a tremendous time waster. Without identifying, verifying, and removing the root cause of the problem, teams almost always fall short of reducing variation.

We worked with one company—a chip manufacturer—that for 10 years had tried, unsuccessfully, to resolve a recurring corrosion problem on its custom logic chips. Over the years, numerous process improvement attempts had been made to solve the “corrosion problem”: adding water rinses, O2-Plasmas, polymer strips, etc. All had little or no effect on the problem.

Finally, a SWAT-type team was created to determine the root cause of the “corrosion problem” and take corrective action. During their Problem Analysis, the team discovered that, years previously, an additional step had been put into the manufacturing process in an effort to prevent corrosion. And it was this step that had actually caused the deviation! Eliminating the step saved $108,000 per year in material costs and, more importantly, approximately $2.8 million in yield loss. The costly, decade-long problem caused by leaping to the fix was finally resolved.

6. Faulty Implementation

Let’s face it: Six Sigma interventions are projects. Without a disciplined project management approach, count on running into these difficulties:

Unclear project objectives. The team ends up spinning its wheels, asking over and over, “What are we supposed to accomplish?”

  • Shoddy sequencing. Construction workers are told to put up drywall before the wires have been run through the framing, or paperwork is filed with the FDA before drug trials are completed.
  • Ineffective resource planning. “Surprises” keep cropping up during implementation: “Joe can’t go to your meeting; we’ve got an emergency in our department.” or “There’s nothing in the budget for overtime.”
  • Underinvolvement. Appropriate stakeholders are ignored at key milestones: when a tough problem needs to be solved, a controversial decision made, or a critical approval gotten.
  • Overinvolvement. People are involved unnecessarily, leading to protracted decision making, delayed approvals, and status reviews that take longer than the work itself.
  • Ineffective or delayed monitoring mechanisms. The team’s ability to react is impaired, leading to the all-too-familiar, “Oh, sorry, that already shipped.”
  • Lack of formal project evaluation and closeout. “Lessons learned” do not get captured and communicated. The same problems crop up in subsequent projects.

To avoid this transgression, provide all team members with a common approach to project management and then manage the Six Sigma effort accordingly. Require each team to provide a clear definition of the project’s scope and deliverables prior to planning who’s going to do what, by when. Make sure that the project plan includes clear assignments, accurate sequencing, and realistic timeframes. Don’t forget to think about potential problems at each step in the plan: What problems might arise? What would be likely to cause them? How can you prevent these problems or minimize the damage if they do occur?

Once implementation gets underway, ensure routine monitoring and control by building in milestones and scheduled reviews. Devise a simple visual that shows progress against the schedule, objectives, and costs of the project. We have helped a number of clients develop a “Six Sigma Project Dashboard,” on which all open improvement projects are listed. On the dashboard, they record progress against objectives, schedule, and costs, using red, yellow, and green indicators. A quick glance at the dashboard shows progress against the organization’s entire Six Sigma project portfolio. The dashboard is also linked to specific projects, so when someone needs to “drill down,” they can.

7. Failing to Consider the “Human Side” of Change

At a motorcycle assembly plant where we once worked, a client improvement team designed and installed a new system for recording and reporting defect data. The process required that each defect be recorded on a Final Inspection Card. The defective motorcycles were then repaired and sent on to Pre-Delivery Inspection (PDI).

Associates in PDI were expected to enter the data from the Final Inspection Cards into the computer system, creating a record of the defects. However, only a few defects were listed as choices in the computer, so associates couldn’t always find an accurate description of the defect. Nor was it possible to enter additional problem specification information. In addition, the associates were expected to perform the data entry while meeting production demands and quality standards. The result was extreme frustration among the group. “I can’t find the correct description. I can’t be specific about the problem. Entering the data takes time away from the other jobs they expect me to do.”

Unfortunately, when designing the system the improvement team had never stopped to consider the consequences. For the associates, doing the right thing— entering the data—had only negative consequences. So they just didn’t do it. The cards piled up, and vital information was wasted. This is a fairly common oversight: Technically “right” solutions often overlook the human side of performance.

That “human side” consists of five key elements, all of which must be aligned for Six Sigma to succeed: the Situation, Performer, Response, Consequences, and Feedback, which we abbreviate as SPRCFb and which are illustrated in Figure 2.

For each facet of a Six Sigma project, consider the performance system in which you are asking people to engage:

  • Situation: Whenever employees are put into a new job situation, they need to know exactly what will be expected of them and how their contribution will be measured. And, as changes are made in work processes, they need to know how their job will change and what will be expected of them going forward.
  • Performer: Make sure that your employees—your performers—receive the tools, time, and other resources they need to effectively analyze issues and implement improvements. Focus on providing the appropriate skills and knowledge to the people that are going to be running new and improved processes, and coach them as they begin to put the improvements to work. A common failure: not considering what new skills will be required to sustain the planned improvement.
  • Response: To achieve the response you want from your performers, you need to set up a plan that is realistic and attainable. To do otherwise is to set up your people—and your Six Sigma projects—for failure.
  • Consequences: As you move into the “improve” and “control” phases of your Six Sigma effort, be sure to take into account one of the most common reasons for the failure of change initiatives: an imbalance of consequences. The expectations may be clear and achievable and the skills may be available, but if there are “punishing consequences” for carrying out their work, performers will never buy into it.
  • Feedback: No matter how enthusiastic they are at the outset of a project, a lack of timely, relevant, and accurate feedback is sure to take the wind out of people’s sails. Everyone involved needs to know why projects, ideas, or recommendations are selected; how they doing against their targets; and what the real results are.

End Thoughts

Six Sigma has too much potential to wind up on the “been there, done that” list of failed initiatives. While the seven sins can be deadly, redemption is possible. All it takes is disciplined thinking, a proven approach to solving problems and managing projects, and attention to the people side of performance.


1 Velocci, Anthony L., Jr., “Six Sigma Scores Mixed Results,” Aviation Week and Space Technology, September 30, 2002, Vol. 157, No. 14, p. 56.

2 Ibid.

3 Swayne, Brian, “Where Has All the Magic Gone?”, ASQ Six Sigma Forum Magazine, May 2003, Vol. 2, No. 3, p. 22-27.

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