Six sigma

Six Sigma

Six Sigma is a popular management methodology for process and quality improvement and process defects reduction in an organization. It was developed by Motorola to reduce variations in their manufacturing processes. Six Sigma has evolved over the years and can now be applied to all process of an organization. It has become a widely accepted management strategy in organizations all over the world. Six Sigma methodologies involve constantly analysing and reworking on processes to improve its performance. An organization following six sigma must target to achieve not more than 3.4 defects per million opportunities for a product or service. Six sigma involves statistical measurements and techniques for reduction of defects and performance measurement. In 1991, Motorola certified its first batch of Black Belt Six Sigma experts.  Black Belts, Gold Belts and Green Belts denote the different levels of expertise for six sigma methods implementation. Six Sigma experts use the various six sigma tools to define, measure, analyse, improve and control variations in process quality. This is called the DMAIC Six Sigma approach. Six Sigma experts may also design brand new processes using DFSS (Design for Six Sigma) principles. DFSS is based on the principle that creating new process based on six sigma is more effective than remedying existing defective processes. Implementing Six Sigma methodologies can help an organization reduce costs, reduce wastage of raw materials, improve product quality and maintain it, and increase customer satisfaction. Six Sigma approaches Six Sigma includes two approaches DMAIC and DMADV comprising of five phases each. DMADV is also known as DFSS. As discussed earlier DMAIC is implemented for processes that need to be improved, whereas DMADV is implemented for projects where new processes are created or designed. DMAIC The 5 phases of DMAIC methodology are: Define In the Define phase, the problem or the scope of the project are defined. This phase specifically defines the problem and its possible solutions in detail. It also involves defining the other factors involved in the project like resources, finances, deadlines and the expected outcome after project completion. Measure In the Measure phase, the factors that are critical to the success of the project are identified. These are factors that measure the process performance. Metrics for monitoring the progress of the project are also identified. These help collection of relevant data to assess the degree of success of the project. Analyze The data collected in the previous steps are analyzed in the Analyze phase. This helps distinguish between the critical and trivial causes of a problem. The root cause of a problem can be identified by data analysis. Improve Process improvements are made based on the data analysis to ensure a reduction in the number of defects in processes. Control Controlling the processes is an important final step in DMAIC methodology as it ensures that any deviations from the expected results are corrected in time before they cause any defects. This is a continuous process and must be carried on to ensure that processes run effortlessly and are defect-free. DMADV DMADV methodology is also known as DFSS (Design for Six Sigma) and has five phases: Define Define the design goals of the project based on customer demands and requirements. This includes both internal and external customer demands. Measure Measure and identify CTQ’s (critical to qualities), production process capability, product capabilities and risk assessments. This effectively means measuring customer needs and an organization’s capabilities to meet those needs. Analyze In the analyze phase, based on the customer needs and CTQ’s recognized in the previous step, new ideas and designs are developed. Each of these ideas must be further analyzed and evaluated so that the best and most viable design can be selected. Design In the previous phase, a high-level design is developed. However, in the actual design phase explicit designs are developed and tested. These designs must be evaluated, optimised and prepared for the verification stage. Verify The designs must be verified by setting up simulations and pilot runs.