To finish up our articles on the Six Sigma methodology, this week we will be looking at six sigma DMADV. This stands for determine, measure, analyse, design and verify. It may sound similar to six sigma DMAIC, but the tow should not be confused. In this article we will be giving an overview of the steps of DMADV, as well as its differences and similarities to DMAIC.
What are the Differences between DMAIC and DMADV?
Six sigma DMAIC and DMADV sound fairly similar. In fact, the first three letters of the acronyms stand for exactly the same word. They are not however the same thing, and you can make use of them in subtly different ways. Looking at their similarities to begin with, both are statistically driven tools implemented by buisnesses. They both seek to find solutions to enhancing or driving quality. Both methods are subject to implementation by so called ‘six sigma champions’. Both also work on the common principle of a maximum of 3.4 defects for every million opportunities in a process. Finally both methods seek to achieve goals which satisfy both economic and business objectives.
The main difference is where they are applied, and hence where each is applicable. In DMAIC, the emphasis is on altering or modifying an already existing business process to ensure customer and quality objectives are met. DMADV on the other hand seeks to a create a new process, one which would be free of any quality defects. In other words, DMAIC is ‘defect correction’, whilst DMADV is ‘defect prevention’.
Where DMAIC uses a statistical set of tools to meet its objective, DMADV uses more qualitative tools. DMAIC may focus on one or two critical quality parameters to influence a process. DMADV incorporates all critical quality parameters in a process, aiming to bring large scale quality improvement. The final difference is then the timescale. Where DMAIC may only take a short time scale, DMADV projects end up being much larger and longer processes, often focused on a long term business need for a product or service.
Define, Measure and Analyse
As discussed, the first few steps of both six sigma processes are fairly similar. The first step is to define the project goals in line with those of a customer. In DMAIC this may have been the improvement of quality of a process, where in DMADV it will be the delivery of an entirely new product. Next come measurements. In DMADV, these measurements are of the actual needs and scope of the customer, as opposed to the performance of a process in DMAIC. Then comes the analysis stage. Analysis in the DMAIC methodology is used to interpret the data which had been measured from the existing process and used to determine the root causes of the problem occurring. Analysis in DMADV uses the measurements to find process options which meet the demands of the customers.
The 4th letter of the six sigma acronyms is where the similarities stop between the two methodologies. The fourth step of the DMADV process is design. In this step you need to scrutinise the results of the analysis, and pursue the ones which most align with customer and business objectives. Next comes a detailed design of the new process. After designing, the new process is tested to see if the desired results were obtained. Customers usually provide feedback on the new process before the final service.
The last step of the DMADV process is verification. This isn’t however just the last step to make, but a continuous programme in place. At this stage customer feedback is important in order to make any further changes to the process. This data may lead to simple adjustments or to new applications of the DMADV processes in other areas of the business.