Six Sigma Fundamentals: A Complete Introduction to the System, Methods, and Tools

The aim of the six sigma methodology is improvement in specific projects, authorized by the management, which black belts attack with the intention to remove the "specific" problem. The project has to be worth pursuing with regard to ROI, as well as customer satisfaction. The project is the lifeblood of the entire methodology, and it requires very rigorous investigation, analysis, implementation and follow-up to make sure that the gains claimed become gains realized. It usually follows this pattern:

• Develop the problem statement.

• Determine the problem objective.

• Determine the COPQ parameters.

• Identify CTQ and operational definitions.

• Determine which tools should be used to measure the current status and to prioritize the input variables that contribute to the problem as defined.

• Validate improvement to determine the relationship of Y = f(x...).

• Institutionalize the results in such a way that the gains are sustained.

A suitable project may be identified in various ways. However, the main factors that make a project a suitable candidate for six sigma are that it has:

• Recurring events.

• Narrow scope.

• Available metrics or measurements that can be developed quickly.

• Control of the process.

• Customer satisfaction.

• An annual cost savings target of 250K.

For the project to be effective there are two issues of concern: the project objective and the problem statement. The project objective provides a clear macro statement of the problem. This allows the process owner and team members to focus on what needs to be improved (Y variables). Team members should be specific about the defect, but not include possible solutions. A useful problem statement must have the condition, the criteria, and the measurement. For example, product returns will be reduced to 4% of sales, resulting in a profit impact of $4 million and customer dissatisfaction of 5 percent decrease in the next 12 months.) The problem statement states the goal(s) of the project. It also links to the business objectives through expected output variable performance, ROI impact and project timing. It is important to use enough detail to define success.