Critical To Quality (CTQ)

Quick reference

• 00:05 Hi, I'm Ray Sheen.
• 00:07 Now, there are some terms and
• 00:08 principles that are used constantly at Lean Six Sigma.
• 00:11 It's important that you understand what they mean.
• 00:14 The first of these is CTQ.
• 00:17 CTQ stands for Critical to Quality.
• 00:21 The formal definition is an attribute of a part, assembly, sub-assembly,
• 00:26 product or process that is literally critical to quality or more precisely,
• 00:31 has a direct and significant impact on its actual or perceived quality.
• 00:36 This is the formal definition.
• 00:38 An informal definition will be to say that these
• 00:41 are what the customer cares about most.
• 00:43 Some of the practical applications of this definition
• 00:46 are that these are the drivers of customer needs.
• 00:50 When these are met, the customer is able to achieve their objectives from
• 00:53 the use of product service.
• 00:55 Another practical application is that these need to be measurable.
• 00:58 A customer need of 'fast' is not a CTQ.
• 01:01 To be a CTQ, we need to have specific timing for
• 01:06 fast, such as, ship within 24 hours.
• 01:08 Within a Lean Six Sigma project,
• 01:11 the term CTQ is often used at several different levels or applications.
• 01:16 The first is customer CTQ.
• 01:18 These are externally facing and are the needs of the end customer or user.
• 01:23 These typically deal with the features or attributes of the product or
• 01:26 service that is being offered.
• 01:28 These can change for different types of customers.
• 01:31 Online customers may have different CTQs from customers who buy in a store.
• 01:35 These would also include CTQs from external regulatory or
• 01:39 government agencies who have some requirements that must be met.
• 01:44 We contrast these with the operational CTQs which are sometimes called CTQs for
• 01:48 the internal customer.
• 01:50 These are the CTQs that are associated with running the business.
• 01:54 The product or service must integrate with other business systems and processes.
• 01:58 Also, these are often specific methodologies or practices that are based
• 02:01 upon the function that's associated with the Lean Six Sigma project.
• 02:05 For example, your manufacturing processes may have CTQs associated
• 02:09 with automation equipment with a supply chain network.
• 02:12 And don't think that this only applies to manufacturing.
• 02:15 There may be CTQs on how internal processes operate and
• 02:19 serve the organizations,
• 02:20 such as CTQs on payroll processing or professional development training.
• 02:25 Finally, if you're the Lean Six Sigma team leader,
• 02:28 you need to be aware of any CTQs on how you'll manage your project.
• 02:32 Many organizations have set up requirements for the use of templates or
• 02:36 the conduct of phase reviews.
• 02:38 And your stakeholders may have set constraints on the project,
• 02:41 such as it needs to complete before the end of the fiscal year.
• 02:45 By this time you may be thinking,
• 02:47 well how is this different from listing the customer requirements?
• 02:51 We'll think of CTQs as a unique method for
• 02:54 how those requirements are identified and described.
• 02:56 The team does not work from a sterile multi-page requirements document that
• 03:00 is full of jargon and boiler plate phrases.
• 03:04 Instead, they are using very specific and practical requirements.
• 03:08 Let's consider how we write one.
• 03:10 Start by listing the major function or attribute of the product or
• 03:13 process that the team is analyzing.
• 03:16 For each of those functions,
• 03:17 list specifically what the function lists do from the customer perspective.
• 03:21 That includes both internal and external customers.
• 03:24 And by that I mean we don't describe how it works,
• 03:27 rather we identify what the customer will do with the result when it works.
• 03:32 A great technique that I use to help with this, is that when I list a function,
• 03:36 I start asking the question what does that mean from the customer perspective?
• 03:42 I continue asking that question several times,
• 03:44 until I have a measurable attribute.
• 03:47 Then I'm ready to write it up.
• 03:49 The format I like to use for writing the CTQ is: The product/process
• 03:53 function performs the customer need in this measurable manner.
• 03:59 That tells me what is happening, for what purpose and how to measure success.
• 04:03 Let me walk you through an illustration to show how this works.
• 04:08 This illustration is near and dear to me because I spent a lot of
• 04:11 nights in hotel rooms, as I'm working at the client facility during the day and
• 04:15 working in my hotel at night.
• 04:17 So we start with the product function, in this case,
• 04:20 the work space in the hotel room.
• 04:22 So next there is the customer need with respect to that work space.
• 04:26 I need a comfortable chair,
• 04:27 a desk, several electrical outlets and a strong Internet connection.
• 04:32 Let me take that last one and turn it in to a well written CTQ.
• 04:36 So I ask, what does a strong Internet connection mean?
• 04:39 And I get the answer,
• 04:40 room laptop connects to internet through its wireless system with a strong signal.
• 04:45 That's helpful but its not yet measurable.
• 04:48 So I ask the question again, this time with more specificity.
• 04:52 What does a strong signal mean?
• 04:55 And now I get the answer.
• 04:56 Wireless signal strength at the desk area in each room is at least 4 bars out of 5.
• 05:01 Now that's better, that's something I can measure.
• 05:05 I then put everything into my CTQ format and I get: The room provides a wireless
• 05:10 Internet signal at the desk work space area that is at least 4 bars strong.
• 05:17 Well written CTQ's will make it easier to define the problem and
• 05:21 focus the data collection activities.
• 05:24 Ultimately, project success is based upon achieving the CTQ.

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