Frequently Asked Six Sigma Questions Answered

Question 1: What is the difference between ‘Lean’ and ‘Six Sigma’?

Question 2: How do you sell the concept/ cultural revolution to the organisation and overcome the “what’s in it for me?” from stakeholders?

Question 3: How do you overcome the image of ‘applicable to high volume manufacturing environment’ that the Six Sigma title brings with some senior managers?

Question 4: Doesn’t the act of measurement improve the process anyway?

Question 5: Is developing an initial application to help gather the actual statistics/data for input to a Six Sigma project a leap of faith?

Question 6: A process is only as good as the people using it. How can a business ‘enforce’ the usage, when ‘back doors’ are available (ie they buck the system)?

Question 7: How do you measure how good your process is? What techniques and methods will give/provide most effective results? (For example, the mortgage application form).

Question 8: What are your methods of training?

Question 9: What are the financial benefits of Six Sigma?

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Question 1: What is the difference between ‘Lean’ and ‘Six Sigma’?

We in the Six Sigma Group prefer to think of Lean, Six Sigma, kaizen, corrective action, et al, as being all perspectives of the same process: the process for improving processes. DMAICT is a methodological approach to organise how one approaches a project-based task that has as its objective the improvement of a given aspect of a process. The six serial phases – and within them the iterative steps – are a refinement of Deming’s notable Plan-Do-Check-Act cycle, which is at the heart of all process improvement activity.

It comes down to the complexity of the problems/issues that you are addressing – on the shallow slopes, walking boots and stick are adequate equipment, but as the slope gets steeper, you have to bring out the crampons and axe.

We also describe it as the ‘low hanging fruit’ analogy, but be careful of the limitations of the graphic – you would climb a tree bottom-up, but in a business, you will need to address issues at every level. Complex problems won’t wait for you to pick out all the easy one’s first!

Six Sigma as an Approach

Another view is to consider the nature of the issue as a matrix of ease-benefit:

Prioritisation Matrix

Question 2: How do you sell the concept/ cultural revolution to the organisation and overcome the “what’s in it for me?” from stakeholders?

In the first instance, Six Sigma is a top-down approach and so early introduction involves the education and commitment-building of the senior management. They in turn should be developing a communication strategy that suits their business. Being project-based, Six Sigma activity will focus on improvements to processes (and so to the benefits of reducing costs, errors, improving customer satisfaction) that ought to be on the corporate agenda, anyhow, and have a pressing need to be addressed.

Some of the early work with the senior team is about identifying the issues to be addressed and developing a project cascade to scope bite-sized projects that will be meaningful to the business. Business strategy tools like Hoshin Kanri (creating goal congruence vertically), Balanced Scorecards, EFQM Excellence Model assessments are all helpful here.

In one sense ‘what’s in it for me’ should be: it’s part of your objectives as set by senior management, because they see this as important (because of the goal congruence). At a more personal level – and at the buy-in stage of project input from stakeholders – it’s about addressing local pain-points, solving problems and winning more business. Stakeholder analysis and management is a key tool in the Six Sigma tool portfolio.

Question 3: How do you overcome the image of ‘applicable to high volume manufacturing environment’ that the Six Sigma title brings with some senior managers?

The most direct retort is to show examples of businesses that are actively using Six Sigma and who are not manufacturing companies. Our clientele illustrate a selection of small to large organisations from a wide variety of businesses.

Whilst it is true to say that in the 1990s, Six Sigma was being practised by manufacturing organisations, the New Millennium has seen banks, building societies, insurance companies, the police and hospitals applying Six Sigma to improve their processes, ie reduce costs, improve timeliness and quality of service and so improve customer satisfaction. All businesses have processes and all processes can be improved.

GE, the world’s largest engineering organisation, is often quoted as saving over £2 billion dollars through a concerted effort to improve processes using the Six Sigma methodology. What is not as well known is that two thirds of that was saved in the transactional processes, such as in purchasing, recruiting, finance.

Question 4: Doesn’t the act of measurement improve the process anyway?

The well-known Hawthorne Experiments demonstrated the effect that just being measured caused people to improve their performance! Six Sigma process improvement, however, intends to fix processes permanently and sustainability is a key consideration in the Control phase of DMAICT.

Thinking back to the fruit tree analogy, the fact of the matter is that there are a great deal of issues in any company that are easily fixed, but for the want of attention and a bit of brain application. It would be true to say that the act of measuring a process will flush out quick wins, where a process is very broke. This is where the Blitz Kaizen approach can complement Six Sigma very well, by addressing the ‘low hanging fruit’, of which there is always plenty, and creating a clearer picture of the more complex issues. Blitz Kaizen comes under several names including Workout, 5-day dmaict and rapid improvement workshops.

The solution to more complex problems will not be staring you in the face, however, and it will take data analysis just to understand what’s going on. The matrix below is another way of thinking about it:

Types of Improvement Project

Question 5: Is developing an initial application to help gather the actual statistics/data for input to a Six Sigma project a leap of faith?

If you are troubled by a process problem, you will have to be able to quantify it, if you are to understand it. Collecting data is just sound common sense.

Some problems are not complex and we would not advocate a sledgehammer approach to all issues. However, be cautious of the impatience for results that seduces people to jump directly to a solution. Six Sigma is powerful in that it draws conclusions from data – decisions are made from facts. Where problems are complex, the causes are not always obvious and the temptation to put in a ‘fix’ may at best give a reprieve and at worst cost a lot of money and heart-ache without giving any improved results.

Sometimes, the decision to gather data around a problem yields the conclusion that a problem was not actually real but a false perception and there is no fix to be had. This marks a good result, as it means we do not have to waste our valuable time pursuing a mirage.

Question 6: A process is only as good as the people using it. How can a business ‘enforce’ the usage, when ‘back doors’ are available (ie they buck the system)?

To quote W Edwards Deming, the eminent quality guru:

“Eighty-five percent of the reasons for failure to meet customer expectations are related to deficiencies in systems and process… rather than the employee.

The role of management is to change the process rather than badger individuals to do better.”

People will buck the process for a variety of reasons, not least of which the process is poor and they have found a more efficient and effective way of achieving the same output, in which case that should be recognised and the process altered to suit.

Of course, if bucking the procedures leads to errors, then there is an issue. Why do people ‘use the back door’? It may be instilled behaviour through the way in which they are measured (I know a bus driver who jumps red lights to keep to the scheduled timetable, because he is measured on bus stop arrival times!); it may be complexity, it may be ignorance, it may be home time.

The trick is to make the process the preferred way of doing it (like lightning, people will follow the path of least resistance), to measure the things you want as output (such as quality), to be sure that people understand what and why something is important and appreciate the process steps up and downstream of themselves and to make the process difficult to get wrong by using an approach we call Poka Yoke.

Poka Yoke means mistake-proofing the process – identify the steps that you must critically get right ( a tool called Failure Modes and Effects Analysis can be helpful there) and (re)design the process so that it becomes very difficult – if not impossible – to get it wrong. There are simple, every day examples – if you leave your car lights on, you get a warning buzzer; you can’t fit a diesel pump dispenser into an unleaded tank (or is it the other way around…); window envelopes eliminate the possibility of putting an addressed letter or invoice into an envelope that is differently labeled (could be embarrassing at best, you might never get paid or perhaps sued at worst); mandatory fields on computer-based forms that defy you to jump to the next page of an application.

The author of the question is right: processes – especially transactional processes fall down where people are involved. Part of solutions design, then, is to create processes that minimise the errors and the impact of those errors. (It will have occurred to you that part of the solution is to automate the process and eliminate the people factor…valid in some cases, eg doing cheque runs, but impossible to achieve completely).

If you involve the process members themselves in the redesign, you will build commitment for the new process procedure and they are less likely to ‘use back doors’. As Tom Peters puts it “with every pair of hands you get a free brain”.

Question 7: How do you measure how good your process is? What techniques and methods will give/provide most effective results? (For example, the mortgage application form).

The (R)DMAICT methodology provides the ‘route map’ for first understanding the given process under scrutiny and then changing that process to attain a targeted or required improvement.

The Recognise, Define and Measure phases provide a clear set of tools and approach to measuring how good your process is.

In the first instance, it will have been Recognised that a particular process requires attention and this is a pre-define phase in which projects are identified and selected for the ‘DMAICT treatment’.

As part of Define, there is a ‘Voice of the Customer’ translation conducted, out of which we identify the CTQs – the Critical to Quality issues that a customer (the recipient of the output of the process) cares about and which we can measure.

We also draw a high-level process map, known as a SIPOC, to scope the process (ie where does it start and end) and so scope the project size.

If the process we were looking to improve was that of completing mortgage application forms without ‘spoils’, for example, we would need to define who is the customer (is it the approvals department, say, who accept/reject an application) and then we would focus on an aspect of the process, in this case we would have to decide where we felt the process began – when a sales rep sat with an applicant and filled out the form? What was that process from that point to the point where the form was deemed to be rejected? What counts as a ‘reject’ (ie as a spoilt application)? The CTQ definitions will give us a defect definition.

We can also estimate the ‘size of the prize’ – if spoilt papers requires that the process be done again, returning to the applicant and refilling the form, say, then there will be an estimable cost of that first-time failure. If this happened five forms in a hundred, we could declare the cost associated with that particular error and estimate the savings if we reduced the rejection rate.

The CTQs form the basis for the process measurements, from which we can then assess how good a process is. Each CTQ will relate to an output measure we call a ‘Y’ and the variation in the ‘Y’ is a result of the variation in the process inputs and what we in the process do with those inputs. These we call ‘X’s.

CTQ's Ys and Xs

The Measure phase deals with establishing a data collection plan to collect data relating to the Xs (and the Ys) and then proceeds to collect the data.

In the example, the Y might be ‘number of unspoilt applications in a given time period’ . The Xs would include many things and are typically captured on a fishbone diagram:

Fishbone Diagrams

Typical Xs might include: the sales rep, the time of day, the mode of interview (over the phone, face-to-face), mode of capture (pen and paper, computer…) and each of these will break down still further. Some of these will eventually be identified as the root causes of the spoils – the sources of variation.

When we have collected data, we can calculate the capability of the process as it stands and we call this a Baseline process capability. In essence, we are looking at how well the process, with the variation in its output, fits the ‘window’ of acceptable limits, as defined by the Customer (and is in fact the CTQ).

Six Sigma in a Nutshell

In Six Sigma, we convert this measure of ‘fit’ into a Sigma Value, which effectively is representing a ratio of the area under the variation curve that fell outside of the customer’s limits to that which met and satisfied the customer.

If, for example, out of one hundred mortgage application forms, 5% were found to have sufficient number of errors to be declared ‘spoilt’ and so were rejected on first pass, we could equate this to a Defects Per Million Opportunity (DPMO) count of 50,000, which can be equated statistically to a Sigma Value of 3.14. If we improved the error rate to just 2 in a hundred, we would now have a Sigma Value of 3.55 (a Sigma Value of 6.0 would relate to only 3.4 errors in a million!)

(Note – I have simplified this somewhat and the statistically minded amongst you will know that there are complexities involved, depending on what we count as errors, long term and short term data, continuous or discrete data and other factors).

Below is an equivalence table that shows different ways of representing the process performance.

Measuring Process Performance

Question 8: What are your methods of training?

In the Six Sigma Group, we consider that Lean principles and Six Sigma Process Improvement are two parts of a continuous spectrum of business performance improvement (that also includes at one end Kaizen and Corrective Action and at the other Design for Six Sigma).

Our materials reflect this philosophy in that they incorporate both Lean and the DMAICT tools and techniques under the one title of Six Sigma. We feel that to do otherwise is to present the opportunity for confusion amongst practising companies. We have included a ‘T – Transfer’ phase in the DMAIC methodology. This is to create an overt team activity to ensure that maximum leverage from project work is gained through the proactive sharing of knowledge with all relevant parts of the organisation.

Our training materials receive praise from our clients for their clarity and comprehensiveness. We provide a complete hard copy of all necessary materials for each delegate plus a CD copy. Minitab training is integrated into our standard 10-day Green Belt and 20-day Black Belt courses and full documentation is provided together with a training version of Minitab software. The courses are modular and spread over several months (typically a module per month) and the training follows the project methodology, DMAICT. Delegates are expected to conduct a project from the outset and so benefit from some project advice each module.

Our people consist of experienced trainers and consultants, who have worked on improvement projects and managed project teams in a variety of companies

Our standard of tuition and project application support is high. To maintain a high quality of delivery we ensure that a team of tutor/consultants is allocated to a contract. This enables us to get to know your organisation and encourages a team relationship to develop.

The delivery team consists of a programme manager and at least one other tutor/consultant. This is typically augmented by one or two other consultants appropriate to the module subject matter (e.g. we may use a ‘soft skills’ expert for parts of the change management content).

Question 9: What are the financial benefits of Six Sigma?

Typically benefits are measured on project savings. A Green Belt project may return around £50k savings and a Black Belt project £100k-£250k. In any one training course, each delegate will be expected to lead a project, so the training costs can be expected to be returned many times over.

Taking into account the company effort in executing projects (not just the time of the Belt, but also the team members and other stakeholders), you can look for a return of 5x the cost.