It can be said that the joint implementation of the DFSS and Six Sigma is important because they augment and complement each other. Understanding how the two work and where they differ in characteristics is very important for the workforce of any organization. From what I learnt I can say that a key element to use or combine both approaches is to understand that DFSS is an inductive process analysis while the Six Sigma using DMAIC is a deductive analysis. Both of them have some limitations that can be overcome using proper techniques from the other one. To explain that I would try to mention some of the approaches limitation and how to overcome them using the other ones practices which might be helpful in future implementation.
1) DFSS procedure does not have a universal application: Six Sigma DMAIC can be used as a complementary tool. This is because the Six Sigma has a standardized way of application, whereas the Design for Six Sigma is customized according to the organization so a company can modify SS in their desire to come up with proper tools. DMADV, DCCDI, IDOV, DMEDI are all modified tools used by companies to apply DFSS.
2) DFSS focuses much on the final engineering optimization processes. This means that the finer details of products and services which should satisfy the customer may be missed out. The use of Six Sigma is important here because it assists in improving the processes which may have been missed out by the DFSS.
3) In a manufacturing set-up, the DFSS can only focus on initiating processes to reduce machine breakdown time. DMAIC goes further to look at different aspects of this machine breakdown before improving on the system. In such a situation, the case will have been dealt with at the micro and the macro scale.
4) Applying DFSS from the beginning will ease the job of defect reduction. A case in point is a defects reduction program in a factory. Six Sigma cannot implement such a process; however, DFSS can implement it easily. Six Sigma can then improve on the process.