One of the quality metrics used in almost all industries is Six Sigma. It is actually a business management strategy. The aim of which is to improve process quality and the quality of the output. The factors that are responsible for the defects in the system are identified and steps to minimize them are taken. The processes used in Six Sigma have their origin in Deming's Plan-Do-Check-Act (PDCA) Cycle. DMAIC and DMADV are the processes, which make up Six Sigma. This starts the debate DMAIC against DMADV, as both of them seem to be similar. Although they look similar, they are way different from one another. Let's understand how.
The acronym DMAIC stands for Define, Measure, Analyze, Improve, Control. The define phase is the most important phase of DMAIC process. It is in this step that the problem is defined, the process to be undertaken is identified and project goals are set up. The perspective of the customer has to be taken into account. Unlike the other methodologies, there is a lot of importance given to identifying the problem. Often quantitative terms are used for measuring the problem.
In the measure phase, the data necessary for the process is gathered from all possible quarters. The key aspects of the current process are taken into consideration and noted down. Once the data has been gathered the data is measured against different parameters. This action helps in determining the factors, which influence the end result of the process.
The third phase is the analyze phase, where the gathered data is analyzed, using different statistical tools. This analysis helps in deeper understanding of the problem. The cause and effect relationship of various factors is taken into consideration. Measures are taken, so that no factor of the process is left out of the analysis. Once the root cause has been identified, it becomes easier to work on the process and solve the problem at hand.
After the analyze phase comes the improve phase. The process development is carried out using different techniques, which help in establishing process capability. The data gathered and analyzed has an important role to play in the improvement phase. Different solutions to the problems are first identified and after analyzing the pros and cons of each of them, the best of them all is adopted for the said process.
The last is the control phase. So that the development, which was brought about does not deviate from the goal set, control mechanisms are set up. In case of any variance, the problem is identified immediately and measures are taken to rectify the problem. Often there is a process monitoring team that is set up, which gives inputs, that helps in bettering the process.
DMADV stands for Define, Measure, Analyze, Design and Verify. Like in DMAIC, the first phase of the DMADV process is the define phase. In this phase the goal of the process is designed, taking the needs of the customer into consideration along with the goal of the organization. At the same time, internal goals for the company working on the DMADV are also set up.
In the measure phase, the critical to quality aspects are identified and measured. The product capabilities, risks, etc. are also identified and quantified. This helps in better understanding of the goal of the customer.
The next phase is the analyze phase, where the data gathered and quantified is analyzed. This analysis is used for developing and designing alternatives. High level design is created with the analysis and the capability of the design to give results and its stability, are tested. Using the test results, the best of the alternatives from the design are chosen.
In the design phase, the design from the analyze phase is optimized further. A verification plan is set up, which helps in analyzing the design. The aim of this phase is to ensure that the right process is chosen, so that there is no place for any kind of error and the design is efficiently able to meet the target.
The last of the phases in DMADV is the verify phase. Once the optimum design has been chosen, it is verified. Simulation may be used for verifying the design. Test runs are carried out to verify that the process designed works fine and is able to meet the target with almost no place for defects of any kind in it. Once the results are positive, the process is implemented and handed over to the customer.
DMADV Vs. DMAIC
After reading about the DMAIC and DMADV methodologies, we will now turn to find out the difference between DMAIC and DMADV. If one has to take a superficial look at both DMAIC and DMADV, then the difference lies in the last two phases of the process. However, the difference is much deeper and where each one of these methodologies can be implemented.
DMADV is used, when a new system has to be implemented. It takes the customer needs into consideration vis-a-vis product or service. On the other hand, DMAIC works on an existing process. The business process is defined along with the method of its application. Hence, it is DMAIC which is used for measuring and assessing the current performance of the existing system. While it is DMADV, which measures the requirements of the customer, along with the specifications in detail.
The next point in the debate is the area of work of each one of them. Since DMAIC process is already in place, the problem at hand is analyzed to nail the root cause of the problem and the issue, which is giving rise to the problem. This in turn helps in nailing the factor, which causes the quality of the product or service to dwindle. Once the said loopholes are fixed, the defects or errors go down to almost none. On other hand, in DMADV, different business process are identified, which can prove to be of help to the customer. Hence, often different processes have to be tested for checking its capability and stability.
While DMAIC helps in eliminating the errors, it is DMADV which helps in fulfilling the needs of the customer. Therefore, once DMAIC is implemented for a process, there are different control mechanisms, which are set up. These mechanisms help in keeping a tab on the process and check for variances. In case any sort of variances are noted, immediate measures are taken and the variance nullified.
On the other hand, in DMADV the process is made. And it has to go through different simulation tests. These tests help in assessing whether the new system will efficiently be able to meet the requirements of the customer. Hence, often a number of different options are tested for the same to rule out any area of defect.
The summary of the debate is that DMADV is used for developing new systems, while DMAIC works on an existing system, to make the system defect and/or error free. Hence, they cannot be interchanged for one another. If the aim is to consistently manufacture products or given services that have no place for errors, it is best to have the process set up using DMADV and modified at regular intervals using DMAIC.