Six Sigma Model Concept
Six Sigma is a quality management model, initially developed and implemented by Motorola in 1986 and based on the statistic works of Joseph Juran. The model supplies a set of tools destined to improve the capacity of the company’s business processes. The term sigma is a Greek symbol used statistically to measure processes’ deviations referent to the optimal.
The central idea of the model is that it is possible to measure the defects quantity in a certain process, so it is also possible in a systematic way how these are eliminated, approaching them of the “zero-defects”. It’s, therefore a methodology that concentrates in the prevention of defects through the use of statistic tools, being applicable to any process inside the organization.
Participants in the Implementation Process
Despite being a model which implies the deployment of all organization, for the implementation of this model is necessary the creation of a human structure, of which are part the following groups:
- Top Management: Establishes the goals to achieve, creates the necessary organizational infrastructure, selects projects and the teams to perform them, provides the support needed and monitors during the phases of the project.
- Champion: Is a member of the top management responsible for logistics and the programs business aspects. Offers his capacity of management, leadership, support and guides to the Black Belt group.
- Black Belts: Are leaders of the team responsible for measuring, analysis, improvement and control of the processes which influence the clients’ satisfaction and the productivity growth.
- Green Belts: Are the individuals who support the implementation and application of the Six Sigma tools, through the participation in project teams.
- Black Belt Master: Is the teacher and mentor of the Black Belts. Offers support, reviews projects and carries out wide scale projects. He performs as internal consultant, trainer and expert.
Project Implementation Phases
The Six Sigma Methodology includes a set of tools that should be implemented according to a systematic methodology and guided for the project, through a cycle formed by the following phases, namely:
The application of the methodology begins with and exam of the aspects related with a specific problem or a group of projects, involving the following activities:
Identification of the possible projects to perform; projects evaluation; project selection (based on the “Cost Not Quality” criteria”); preparation of the projects’ Mission; Team selection and Begin of the work.
The goal of this phase is to identify and document the processes’ parameters which affect its functioning and the products characteristics critical for the client: begin the process characterization; data collection planning; measuring system validation; process capacity measure.
Concluded the measurement phase can now be determined which variables have a more probable impact in the most important attributes for the Client: data collection and analysis; development and validation of hypothesis about the variation sources and the cause-effect relations; confirmation of the process functioning determinants.
Planning of experiments – the called DOE (Design Of Experiments); performance of the experiments to identify critical determinants; performance of the experiments to determine the mathematic model of the process functioning; optimization of the process functioning, using techniques such as answer surface methods and evolutionary operation (EVOP).
Control conception and documentation of process improvements; measuring system validation; process capacity determination; implementation and monitoring performance.