It's no surprise that this one pops up often in Quality Manager Interviews. Six sigma has 2 majorly popular and widely used methodologies - DMAIC (Define, Measure, Analyze, Improve, Control) and DMADV (Define, Measure, Analyze, Design, Verify) which aim at the elimination of waste and reducing the variations from processes. Both DMAIC and DMADV are Lean six sigma principles and while DMAIC focuses on improvements in current processes, DMADV focuses on improvements in the design of new processes, products, and services.  The objective of the DMAIC methodology is to improve an existing process by performing the following phases:  Define - Defining the problems, outputs, customers, and processes associated with the problem  Measure - Data collection to establish a benchmark for improvements  Analyze - Analysis of data to find the root cause of defects  Improve - Develop, test, and implement solutions to improve the processes  Control - Establish process controls to sustain improvements  The objective of the DMADV methodology is to design a new product, service, or process by performing the following phases:  Define - Define the process and design goals  Measure - Identify and measure the CTQs (Critical-to-quality) attributes  Analyze - Perform data analysis to determine the best design  Design - Design and validate the product, service, or process  Verify - Perform verification and validation methods to evaluate the output  In certain cases organizations also use an alternate methodology that adds a phase of optimization to the DMADV making it DMADVO which strives to optimize the design post-implementation. DMAIC, DMADV and Six Sigma techniques are important areas candidates must understand before appearing or preparing for the quality manager round interview questions.