I notice that most people misunderstanding ‘Design Thinking’ for ‘Design of Six Sigma(DFSS)’. The latter is an approach within Six Sigma to develop new products or services. In reality Design Thinking and DFSS are different animals, but not mutually exclusive.
Here’s how i see it:
Six Sigma offers a systematic way to improve or design products/service. It brings tools, methodology and rigor into the process.
Design thinking is the way designers think! Designers have nothing in front of them, but they visualize, experiment, hypothesize, iterate and iterate before coming up with the final output. There are variety of tools they use such as Journey Mapping, Mind Mapping, Visualization, Story boarding, Co-creation, Assumption Testing, Rapid Prototyping (& piloting), learning launch, etc.,
The being a practitioner of both these approaches, I think ONE most significant difference is that – Six Sigma thinking process is linear (but allows iteration). On the other hand, Design Thinking process is iterative (but allows linear progression).
Second difference is that Six Sigma emphasizes more of data rigor (& less of creative rigor – imaginative aspects). Design Thinking emphasizes more of imaginative rigor (& less of data rigor).
So it must be obvious that both are not certainly mutually exclusive, but they are very different!
Design Thinking has seeing a lot of traction in Service Sector, because traditional service design never followed any rigorous process.