Design for Six Sigma (DFSS) is an approach that is part of the Six Sigma methodology, and it aims to develop products and services which operate at Six Sigma or above. What does this mean; and how is this approach different from implementing six sigma in existing products, services & processes? If you have read our articles What is Six in Six Sigma, and What is Sigma in Six Sigma; you will understand how Six Sigma is measured.
Every process performs at its designed and operating capability. For instance, consider the Indian traffic and transportation management system. A good measure of its performance is the number of deaths due to road accidents. There are several other measures, but for simplicity let’s just consider this one. This performance measure is called CTQ (Critical To Quality).
India has the largest number of deaths per year due to road accidents (Approximately 130,000 deaths per annum). If we were to commence a Six Sigma project to reduce the number of deaths, we would use DMAIC approach. We will identify root causes for this problem, and try to eliminate them with good and sustainable solutions. For instance, helmets and seat belts mandatory, enforcement of speed limits & drunken driving laws, additional traffic patrols, etc., may be few solutions we will implement.

By doing so, lets hypothetically assume that we have been able to reduce the number of deaths to 30,000 per annum, in 3 years’ time. However, we aren’t able to reduce it any further. This stage; when any process or system is delivering its best performance, is referred to as Process Entitlement.
However, 30,000 is still a high number and we want to bring it down to manageable double digits. So we have to discard our existing traffic & transport management system; and design a completely new system, from scratch, that will help us reach our target. Double digit fatality means we will operate well within Six Sigma level, considering our 1.2 billion population as a base.
Such a process of re-designing or newly designing any product, service or products is referred to as DFSS. Design for Six Sigma is defined as a Customer focused design approach used for creating products, services, and processes which will deliver Six Sigma Performance. Samsung products are a very good example of Design for Six Sigma.
In many fields like airline, surgery, automobile braking, etc., require processes to deliver Six Sigma at all times. For such systems, design for six sigma concept comes handy. The very first time products and processes are developed, they are designed to deliver Six Sigma performance.
Following are the key differentiators for DFSS:

  • Understand customer requirements, and translate them to product performance measures.
  • Design products, sub-systems, and processes to deliver Six Sigma performance.
  • Design ‘first time right’ products and services.
  • Innovative designs deliver Six Sigma performance, rather than existing designs.
  • Optimize the design for usability, manufacturability, or serviceability.

While DFSS is a principle, there are different ways in which it can be put to use. IDOV and DMADV are popular approaches.

IDOV is a 4 step approach representing Identify, Design, Optimize & Verify.  And DMADV is a 5 step approach representing Define, Measure, Analyze, Design & Verify.