Six Sigma - DMAIC Explained.

Six Sigma is a Performance goal, representing a quality level that meets standards for 3.4 defects per million opportunities.

It uses series of tools and methods used to improve existing processes (DMAIC) or design products, processes and/or services (DMADV). The principle of Six Sigma involves around improving the processes, using statistical measure indicating the number of standard deviations, to a quality level so as to meet and maintain quality standard requirement of 3.4 defects per million opportunities.

The core principle of Six Sigma revolves around discipline and fact-based approach to manage business and its surrounding process framework. In this post I'm mentioning details about DMAIC methodologies which can be used to improve existing processes in a organization.

DMAIC stands for Define, Measure, Analyze, Improve and Control. This is one of the key methodology followed in Six Sigma. I'm trying to explain briefly the key areas covered in the cycle for easier understanding.


#1 Define - This process group is used to:
      1. Define the problem statement
      2. Preparing the charter and goals
      3. Voice of the customer (Pain areas)
      4. Understanding customer expectations e.g. Kano model
      5. Define Process Maps
      6. SIPOC (Supplier Input Process Output Customer) definition



# 2 Measure - This process group is primarily used to measure data for data capturing processes:
       1. Identify key aspects of the current process
       2. Identify Critical to Quality (CTQ) tree 
       3. Stratification of data
       4. Identifying data to be captured
       5. Collect relevant data for analysis


# 3 Analyze - This process group is used to analyze data and identify any findings, trends and causes
       1. Investigate the data collected
       2. Determine what dependencies and relationship between various parameters
       3. Seek out root cause of the defect under investigation (Normal causes Vs. Special causes)
       4. Analyzing data using tools of Six Sigma i.e. Flow charts, Histogram, Pareto chart,Run chart, Scatter Plot, Control charts and Cause and Effect diagram


# 4 Improve - This is used to improve and/or optimize the current process:
       1. Data analysis using techniques such as design of experiments, mistake proofing
       2. Standard work to create a new or future state process
       3. Proof of concept (POC) to establish any changes
       4. Set up pilot runs to establish process capability
       5. Removing Delays, Decisions points and Overheads from the existing processes


# 5 Control - This process group is used to define control parameters and then monitor data based on the parameters:
       1. Define control parameters
       2. Defining and monitoring of thresholds
       3. Continuously monitor data using control charts
       4. Prevention mechanisms implementations
       5. Define contingency and/or Action plan

How much quality is good enough?

Imagine if somebody says 'The quality of a product is 99% defect free'. Seems like WOW!! isn't it?

Think again. In term of deviation this (99% accuracy) stands at around 4 Sigma which means around 6000 defects per million opportunities. Now consider this:

3 Sigma is 93.3% accuracy - 66807 defects per million opportunities
4 sigma is 99.38% accuracy - 6210 defects per million opportunities
5 sigma is 99.97% accuracy - 233 defects per million opportunities
6 sigma is 99.99966% accuracy - 3.4 defects per million opportunities
7 sigma is 99.9999981% accuracy - 0.019 defects per million opportunities

Now let's compare some data:

1. If we send 3 Million letters to the users that means
1. With 4 sigma we will lose 3000 letters
2. With 6 sigma we will lose only 1
2. For every week of TV broadcasting per channel
1. With 4 sigma 1.7 hours of dead air broadcast
2. With 6 sigma 1.8 seconds of dead air broadcast
3. Out of every 500,000 computer restarts
1. With 4 sigma around 4000 system crashes
2. With 6 sigma Less than 2 system crashes 
4. Total flight canceled in US every 3 weeks
1. With 3 sigma 964 flights cancellations in a day
2. With 4 sigma 30 flights cancellations
3. With 6 sigma 1 flight cancellations

Many of the spaceship and medical advancement projects runs at more than 7+ sigma quality standard as there are no scope whatsoever, for errors, due to the level of cost, time and importance surrounding those projects.

Amazingly, mumbai dabbawalas stands at a whopping 7+ sigma (only 1 defect in 6 Million opportunities). This is a really amazing, considering that most of the workers (5000 workers and 170 thousand lunch boxes a day) are uneducated and uses only a color code system to identify lunch boxes. Who says to be high quality processes it needs to be complex. Instead it just needed to be simple and effective!! Isn't it?

Currently we do not see many IT organizations implementing Six Sigma level processes and only very few organizations implementing this practice. In future we might see such level of quality implemented in IT projects but that may be some time, from now. Many organizations desist from this practice as short term investment might be high and returns are primarily long term only.

BTW, you can also get sigma values for some of the things around you e.g.: 'Number of defects per million line of code' or 'Number of defect you found per thousand test steps' and check the sigma value for the same...Have fun.

How to Solve customer problems by identifying Critical to Quality (CTQ) approach.

Many a times we are faced with situations with problems being reports from customers. If we do not look into the problems quickly and handle them carefully then we may end up with unwanted escalations and loss of business opportunities.

To manage customer problems there are many frameworks available that helps understand the problem areas and then work towards correcting them. One of such technique is Voice of Customer (VOC) to Critical to Quality (CTQ) mapping techniques in Six Sigma. This is a very effective methodology to understand and solve customer problems very quickly and effectively. Some of the elements that we need to consider for this are listed below:

1. Identify Voice of Customer (VOC) - It is very important to understand the customer problems clearly. This may include carefully examine feedback provided by customer, talking directly to customers or getting details from customer issue base etc.
2. Service/Quality Affected - Once you identify the problem customer is reporting then try to map this to a specific Service/Quality Area. This will help in alignment of identifying team and other resources needed to resolve the problem.
3. Customer Expectations - Try to understand what exactly customer needs. If the need is understood correctly then you can target the corrective measures effectively.
4. Critical to Quality (CTQ) measurement - Identify the CTQ data measurement that will help you evaluate whether the exact problem is solved or not with the suggested corrective actions. This will also define benchmark for tracking and identification of improvement in future.
5. Action Items - This will help tracking of various action items that are identified while solving the problem. 

I'm giving an example for your easier understanding of this methodology:

Voice of Customer (VOC)	Service/Quality Area Affected	Customer Expectations	Critical To Quality (CTQ)
Customers complains that bills are either not provided to them or not delivered timely	Inconsistency of Billing cycle	Bill needs to be delivered consistently  and on time	Bill needs to be delivered on 10th of every month with a exception of +/- 1 day