What is the typical methodology of six sigma? | Six Sigma Fundamentals: A Complete Introduction to the System, Methods, and Tools

There are several approaches to six sigma. The three predominant ones are:

The Motorola approach. Motorola was the first company to develop the methodology and they focused on six steps:
1. Identifying the product you create or the service you provide.
2. Identifying the customers for your product or service and determining what they consider important.
3. Identifying your needs (i.e., to provide products or services that satisfy the customer).
4. Defining the process for doing the work.
5. Mistake-proofing the process and eliminating wasted effort.
6. Ensuring continual improvement by measuring, analyzing and controlling the improved process.
The Six Sigma Academy approach. This is the first commercially accepted methodology of six sigma, with minor variations, from the original Motorola approach. Indeed, it is the first six sigma methodology to which most organizations were exposed early in the life of the methodology. It is a simple, popular and straightforward approach. It focuses on four major phases:
1. Measure.
2. Analyze.
3. Improve.
4. Control.
The General Electric approach. General Electric was the company that continued the progress of Motorola and standardized the methodology. GE's approach has become the de facto approach of most organizations with some very small variations. GE focused on the following five steps, which together make up the DMAIC model:
1. Define—identify the improvement opportunity.
2. Measure—account for the current performance.
3. Analyze—evaluate the primary contributors.
4. Improve—enhance the operation or process.
5. Control—regulate (verify) the improved operation or process.

Yet another approach to six sigma is the understanding that improvement may be attained in current and future products and services. As a result of this thinking, design for six sigma (DFSS) came to be an addition to the traditional approach. The traditional approach is the DMAIC model and the define, characterize, optimize, verify (DCOV) is the newer addition.