What is Six Sigma: Ultimate step-by-step guide

You've probably heard of Six Sigma.

But do you have the ULTIMATE step-by-step guide for implementating 6 Sigma?

Well that's where this post comes in.

My view:

As a Software Business Analyst, there are so many aspects of six sigma that we could use to improve our project outcomes.

So here's my side of the deal..

I'm giving you a detailed step by step guide to 6 Sigma methodology.

Then I'm comparing it to the ISEB Business Analysis Planning framework.

Before clearly explaining my secrets on how you can use the six sigma benefits.

6 Sigma is heavily statistical and a change methodology for ELIMINATING defects in any process. Founded in manufacturing but has stormed the transactional processing industry, such as finance, in recent years. If a company is achieving 6 sigma, they are losing only 3.4 products out of a possible 1,000,000 (1 million) produced. Likewise they are making only 3.4 errors for every million opportunities when processing transactions.

Many frameworks are in operation for 6 Sigma.

But, one of the most common is DMAIC

And that’s what I’m using to explain the technique.

What is Six Sigma DMAIC?

DMAIC stands for Define, Measure, Analyse, Improve, Control

what is six sigma

However, Change DOES NOT guarantee improvement

It’s believed 90% of a company’s problems can be solved with just 7 basic tools:

what is six sigma

And I’ll touch on all of these tools and techiques throughout this post

An Introduction to Business Analysis Practice framework

An IT Business Analyst may never use Six Sigma

So this is what the Business Analysis Practice certification teaches you.

And when implemented properly, provides a excellent framework for replacing manual processes with brand new systems

But there’s 3 reasons it ‘fails’ compared to 6 Sigma…


Because there’s very little focus on teaching BAs that STATISTICS ARE KING!

I’m telling you now:

There’s only one way of proving your findings and recommendations to the CEO -

By backing them up with clear, well thought-out statistical analysis.

Before I give you the second reason, let me show you this

The Business Analysis framework:

what is six sigma

While, the BA framework is focussed on a project lifecycle, which means it has an end. 6 Sigma is continuous. It never ends. It drives an organisational culture.

When a BA finishes a project, they may move onto something completely different, unrelated.

Meaning a possible lack of long term stability.

When Six Sigma sub-project is finished, the next one begins as part of the 6 sigma organisation improvement programme.

Once a company achieves level 6 in 6 sigma, they must continue to change AND improve.

But lets be honest – Do Projects EVER end when adopting the standard BA project framework for system implementation? Probably not - they are either late, fail or too costly to finish

Which leads me to my 3rd reason for failure…

It’s a 21st century revolution for software development called AGILE.

If you’ve not yet heard of Agile you will very soon.

And even though it’s outside the scope of this post. My blog will undoubtedly begin to become more Agile focussed.

But the standard BA framework tells you to gather all requirements up front prior to beginning development.

It’s becoming old fashioned.

People are finally realising that you can’t possibly PLAN and gather ALL requirements, up front, for 2 years before delivering CRAP to the market. Which does happen in a lot of projects.

Rant over…

Six Sigma – DEFINE the project

The first step is to LAUNCH the project.

The goal?

Prove why a certain problem is important.

Here you will:

1. Brainstorm the list of problems & Select the most important to improve

Great for making employees feel involved right from the off

See my video on Workshop techniques

2. Collect customer feedback to identify problems & select the most important to improve

Customers can be internal or external

There are many ways to collect feedback from them. And you don’t even need to collect it yourself

Speak to the marketing team – I bet they already do it.

Ask the customer complaints department. You may have asked the customer complaints team to come to the brainstorming workshop.

3. Collect performance data (quality, cost, delivery, safety)

This is absolutely key!

To achieve this properly 6 sigma style, you will…

Find the database warehouse administrator in your company. He or she will have access to unthinkable amounts of data.

If you don’t know who it is, keep asking until you find them.

Then let them know you’re conducting a high profile project.

Get some data that relates to your brainstorming sessions.

4. Pick a product or service with the largest performance gap

Many companies have a product which is meant to be a high end product but is possibly receiving the most complaints?

That’s what is meant by ‘gap’ in performance.

It might not even be a product, it might be a hugely important transactional process that impacts CASH FLOW and YES 6 sigma can improve these too.

5. Review the organisations strategic plan

All six sigma improvements are driven by the strategic vision of the wider organisation.

So ask the directors if you can see the strategic documents.

Next, in Six Sigma you will:

6. define the project outcomes:

How will the success of the project be measured?

What specific aspect of the product or service needs improvement (Scope – quality, cost, delivery or safety)?

The 3rd task for defining a project is to Identify stakeholders

There’s a number of ways to identify your stakeholders and I’ve written a full post on how to significantly increase stakeholder engagement to your projects.

In short, there’s a few questions you need to ask yourself:

Who are the key people who will be impacted by the project?

How close will they be to the possible changes?

In answering these questions, you will now be able to select the team? Do you need full time employees or just ad-hoc input from colleagues?

Finally create a six sigma project plan

A work breakdown structure OR a Gantt chart is used.

Tip: Don’t spend ages getting the dates perfect because the chances are they WILL change even if it’s just slightly.

Note: when defining the project, you can address issues that might NOT be the most important. That way you get to practice your improvement efforts on the

Business Analysis Framework – Investigate Situation

You could call this…

A combination of the DEFINE (above) and MEASURE (below) in DMAIC

The BA framework adopts a similar approach to defining the project.

BUT with much less emphasis on statistics.

AND projects are usually already decided by the powers.

So your first task will be…

Write a Terms of Reference in the form of a BOSCARD.

Asking questions based on BOSCARD gives you the KEY info as to why the project is being driven by the sponsors.

And there are some stats but not loads.

Next to identify the stakeholders. As in 6 Sigma.

And determine the method stakeholder management for each person. There’s 4 options

- Manage closely

- Keep informed

- Monitor

- Keep satisfied

Stakeholder Power-Interest Grid with Categories

Read my post on how to manage stakeholders using a Power Interest grid

As you can see:

The BA stakeholder approach is very similar to the Six Sigma Stakeholder management approach.


The BA approach quickly moves you onto using elicitation techniques for understanding the situation.

These include:

  • Interviews
  • Workshops
  • Observations
  • Prototyping
  • Scenarios
  • Document Analysis
  • Special Purpose records
  • Questionnaires

  • Pick your techniques carefully – what you do will depend on YOUR situation.

    For example:

    Workshops are good for getting lots of different views all at the same time.

    Where as;

    Interviews are useful when you have one person you know has the knowledge that you need.

    Having collected the information, you will present your findings back to the stakeholders

    This will be done using:

    - Process models

    - Data models

    - Rich pictures

    - Mind maps

    This stage obtains consensus to future requirements.

    So pick you audience carefully and get the right people involved.

    Six Sigma DMAIC – Measure & Observe the Current Situation

    The BA framework pushes you to define the current processes in the first step

    But 6 Sigma allows for a little extra time to analyse the data.

    You are searching for clues.

    The steps to measuring the as-is situation in Six Sigma are…

    1. Define the current process

    How does the process produce the output?

    Six Sigma answers this with the use of flowcharts.

    And there are MANY different techniques.

    SIPOC (Supplier, Input, Customer, Output, Process) is just one of them

    I’ve written a step-by-step post on how to develop a SIPOC Diagram here

    A simple flowchart is another way of identifying how the process works

    Here’s some of the shapes used in a simple flowchart

    what is six sigma process flow

    The responsibility flowchart or SWIM LANE Diagram is another way of mapping the process.

    Created when there are more than one actors or individual doing tasks within a process.

    Layout diagrams may also be used to identify how the process fits together

    Here’s an example of a layout diagram for a drivers licensing office:

    What is six sigma layout diagram

    2. Address 'low hanging fruit' - Quick fixes’

    Experience six sigma practitioners will use their flow diagrams to identify improvement opportunities

    AND implement them early.

    It’s a perfect opportunity Fix the problems that are easy to fix.

    BUT you must ONLY fix what the KNOWN cause of the problems

    AND you know how to MEASURE the improvements

    The fix may be a simple adjustment of the process steps.

    And a simple change could save hours of work

    One approach to identifying improvements is the simple 5S

    What’s 5S?

    Sort – sort out your stuff so it’s easily acessible

    Shine – clean everything

    Set-in Place – choose who will maintain the clean work place

    Standardise – Do the same each time

    Sustain – Ensure all the abive are repeated as often as needed.

    Another technique is to apply the 20 questions strategy to EVERY task on the diagrams:

    3. Obtain customer needs

    If it’s not known EXACTLY what the customer wants or needs.

    Now’s the time to find out.

    Surveys or questionnaires are used to do this

    Or even interviews.

    But the key thing.

    The customer’s needs MUST be transferred into measurable characteristics of your services.

    Known as Critical-to-Quality measures (CTQ )or performance measures

    You will already have some performance data from the DEFINE stage

    But the measure MUST relate to the problem identified.

    Some people like to measure what’s easy, or even worse what looks good.

    For example

    - A customer wants their order on time. Measuring the number of orders sent out each day does not help but it may make the team look good.

    This is avoided in when Six Sigma is implemented properly.

    Remember this too:

    Customers don’t have to be external to the company

    They CAN be internal or even stakeholders of the current project.

    Example of CTQs:

    Customer request

    Fast delivery - Time taken to deliver

    Durable product - Lifespan and reliability level

    Accuracy of processing - number of errors found

    4. Gather initial metrics

    Once it’s known what customers want

    We collect data on the key measures.

    measure the performance of the current process.

    This is done in different ways depending on the type of data

    Measurement – e,g, time, speed, costs

    Count – e.g. Errors, defects,

    Regardless of which tyoe of data is measured, it’s always useful to work out

    1. the mean – average of a set of numbers

    2. Median – the midpoint

    3. Mode – the most frequently appearing

    Other measures of variability include:

    4. Range – difference between the largest and and smallest

    5. Variance – Sum of squared differences (COMPLEX)

    6. Standard Deviation – (COMPLEX)

    5. Determine current Sigma

    Determining current sigma is a very time consuming task.

    In Six Sigma this is an absolute MUST.

    BUT if you’re simply adding six sigma techniques to your BA project, then you don’t really need to do it to such a statistical degree.

    Here’s a six sigma calculator if you have the data and are working on a six sigma project where knowing this is vital

    6. Stratify the data

    Stratifying the data allows you to look at the issues from different angles

    Remember YOU will need to work hard at getting your hands on the data.

    It can be quite difficult.

    But don’t give up.


    Because knowing stats gives you a great position to make very important decisions in the future.


    Look at differences in time, place, type, and symptom of the problem

    Pareto Analysis is a technique that towers above many others due to it’s simple nature.

    20% of the problems cause 80% of the issues.

    Pareto WILL allow you to identify the most impactful problem to address

    Or put even simpler – 80% of your revenue is generated by 20% of your products.

    [IMAGE Pareto chart example]

    Other stratification techniques include:

    Six Sigma Bar charts:

    Six Sigma bar charts will show differences beetween categories

    And the construction of bar charts is very simple:

    Label the vertical axis with the performance unit of measure (UOM) and the horizontal axis with the categories.

    As so...

    what is six sigma pareto analysis

    Six Sigma Pie charts:

    The pie chart shows relative portions of data

    Variables can be broken down into categories such as type, job, department, regon, store.

    It’s the perfect way to stratify the CTQs I mentioned earlier by errors in different times places or areas.

    Now that the data has been stratified.

    It’s time to move on to studying the variation.

    Let’s look at some of the techniques used to do this:

    7. Determine initial value proposition

    In Six Sigma you must clarify the Problem Statement

    By now you will have much more knowledge of the problem(s) at hand

    At this point try to estimate how much money could be saved

    Define or refine any previously determined improvement targets