Customer Requirements

An affinity diagram is a tool that is used to organize a large number of ideas, opinions, and issues and group them based on their relationships. Affinity diagrams are generally used for categorizing ideas that are generated during brainstorming sessions and can be particularly useful for analyzing complex issues.
Affinity Diagrams
The steps for creating an affinity diagram can include:

  1. Generating ideas through brainstorming.
  2. Displaying the ideas randomly.
  3. Sorting the ideas into groups.
  4. Creating header cards for each group to capture the essential links among the ideas in each group.
  5. And, drawing the affinity diagram by writing the problem statement at the top and the headers with their respective groups of ideas below the problem statement.
  6. An affinity diagram helps in sorting and grouping customer requirements.


To gather the VOC, effective methods for accurately capturing customer requirements are required. Several methods are available to capture the VOC.



Quality Function Deployment (QFD) is a structured approach followed by customer-driven organizations to transform customer requirements into their product specifications.HOQ

The House of Quality (HOQ) is a diagram used by a product development team during the initial stage of the QFD process. (more…)


Another roadmap of DFSS is DMADV, an acronym for five interconnected phases, namely Define, Measure, Analyze, Design, and Verify. This methodology is used in projects that involve creating a new product or process design.DMADV

Define – The project goals are defined so that they are in line with customer requirements and enterprise strategies.

Measure – Characteristics that are critical to quality as well as product and process capabilities are measured.

Analyze – The different process options are analyzed and the best process that is consistent with customer requirements is selected.

Design – The details of the process are designed and optimized to meet the needs of customers followed by the performance of the new design which is tested through pilot runs before implementation.

Verify – In this phase the results are test and implementation of new design is carried out for large scale deployment.

Six Sigma has been a successful management approach, and a philosophy for many leading global enterprises. Let’s understand Six Sigma Process – in other words – Six Sigma Deployment Approach.
While the deployment of Six Sigma depends on several factors; the following approach explains Six Sigma process in its simplest form.
Six Sigma as a management discipline puts customer’s interest ahead of others. The process of gathering customer requirements is called as Voice of Customer (VOC). A good deployment program starts with VOC. Customer requirements directly translate into business performance standards. In Six Sigma and many quality management approaches, these performance standards are called as Customer Specification Limits.
Operational metrics and performance measures like KPIs are created based on customer requirements. Such operational measures or KPIs are called as Critical To Quality (CTQ) metrics in Six Sigma.
Output of existing processes is measured against customer requirements. This becomes a benchmark of performance. In Six Sigma, this step is called as Assessment of Current Process Capability.
In case an end-to-end process is not capable of consistently meeting customer requirements, and produces high volume of defects; it is taken up for improvement.
Process improvement approach used in Six Sigma is called as DMAIC. It is the acronym of Define, Measure, Analyze, Improve and Control: a 5 step improvement approach.
In this manner, Six Sigma aims to link Customers, Business Processes, CTQs and process improvement all together.
The real power of a Six Sigma Process is in consistently and iteratively following the above activities.
Thus, an organization following a Six Sigma Process:
  1. Systematically and regularly gathers VOC
  2. Measures its process capability
  3. Identifies improvement opportunities
  4. Uses DMAIC to improve its processes


This is the second article in the series that will help understand What is Six in Six Sigma? If you haven’t already read our article ‘What is Sigma in Six Sigma‘, we would like to recommend that you first do so.
For now, let’s look into what is Six in Six Sigma.
Let’s get started by understanding Customer Requirement and Actual Performance.
We are going to use the example of newspaper delivery everyday to your house. As a customer, you want newspapers to be delivered between 7:00 and 7:30 am (say within a half hour window). However, in reality, the paper gets delivered only between 6:00 to 9:00 am (a 3 hour window). So, in this case, the customer requirement or allowable variation is ’30 mins’ while the Actual Performance or Actual Variation is 3 hours.
On the contrary, your friend isn’t so particular about his newspaper delivery. He is in fact fine if they are delivered between 6:00 to 9:00 am (a 3 hour window). But in reality, his papers get delivered between 7:00 to 7:30 am (a half hour window).
How would you characterize these two situations?

  • In your case, actual variation is much higher than allowable customer requirement. In otWhat is Six in Six Sigmaher words, Standard Deviation or Sigma is high.
  • In your friend’s case, actual variation is much lower than allowable customer requirement (and so, Standard Deviation or Sigma is low)

Now, let’s answer the question ‘What is Six in Six Sigma?’
Six refers to the Sigma Capability of any process. In this case, the newspaper delivery process. When it’s Six, it means that the Standard Deviation or Sigma is so small that 6 Standard Deviations or 6 Sigmas can be fitted on either side of the bell-shaped curve. Based on the principle of bell-shaped curve (normal curve), 6 Sigma equals only 3.4 defects per million opportunities. For the newspaper example, it means that if there are 1 million days of newspaper delivery, only on 3.4 days (i.e. 3 or 4 days) of the delivery will be beyond your requirement. So, it is very obvious that your newspaper delivery isn’t at the Six Sigma level, but your friend’s delivery could be. It depends on the value of Standard Deviation. We covered the computation of standard deviation in ‘What is Sigma in Six Sigma’.
Let’s say for your friend’s process, only 5 standard deviations or sigmas can be fitted on either side of the bell-shaped curve, then, his sigma capability is at 5 or his newspaper delivery process is at 5 Sigma.
To sum up, if you want a particular process to be at Six Sigma, then you will have to manage the following:
Understand what the customer requirement is? If there is a window within which the customer wants her delivery or quality, then that becomes your customer requirement.


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