Six Sigma

In this definition notice the Word “processes”. Six Sigma is a methodology that has as its focus the processes improvement, identifying and eliminating the causes that conduct the process to vary with the time, generating defects. This relationship is demonstrated many times by the use of the equation: Y: f (X1, X2, …Xn). In other words, it leaves to control the outputs of the process to start to monitor its inputs. The Six Sigma methodology is very analytic and contains basic knowledge of statistic and quality tools.

SIX SIGMA METHODOLOGY - DMAIC

Six Sigma Project: This is the format adopted to say that it was identified a process that has impact on the customer satisfaction and for what it Will be formed a Six Sigma team, which Will adopt a systematic methodology to improve it until to reach 3,4 defects per million. It is expected that the project will be concluded in four to six months.
The application of the Six Sigma methodology can be divided in five phases (D-M-A-I-C):

DEFINE (D):
 
In this phase it should be identified what process (Y) of the business will be improved to fulfill a characteristic critical to quality of the customer, improving its satisfaction.

Once the process to be improved was identified, it is said that it is identified a “Six Sigma Project”. It should be verified the economical feasibility of the “project” and it will be done a prediction of the benefits (including the financials) that can be reached.

This phase uses to be simple to be applied in the manufacture line, where there are uncountable processes that generate defected products and thus, it should be improved. For instance: to decrease the manufacture errors of a piece, to decrease reworking and repairs, to decrease the cycle time to execute a task etc. 

In the case of the commercial areas, many times, it is not easy to identify which processes have impact on the customer satisfaction. Besides that, the people do not use to look at your activities as a “process”. Examples of what generates impact on the customer satisfaction in the commercial areas: to decrease the number of mistakes preparing sales orders or invoices, to decrease the lead time to import a product, to decrease the time to answer a customer phone call, to decrease the time to deliver an item requested by a client etc.

The most used tools at this step are: Customer research, Benchmarking, cost-benefit analysis, QFD, Process Map (Macro), Pareto, among others.
 
Measure (M):
 
In this phase, it should be made a general assessment of all process inputs (X´s) and how it relates to the CTQ´s (Critical to quality characteristics) of the client. The process should be mapped.

It should be measured the ability of the process to produce not defected items. In other words, measures the process capability, expressed by its unit sigma.

In this phase, the main used tools are: Process map (detailed), Fishbone, Cause and Effect Matrix, Measure System Analysis and Capability Analyses, as well as basic statistics.

Analyze (A):
 
In this phase, it should be tried variation causes (X´s) that increase the variability of the process and that are accountable by the generation of the defects.

The main tools used are: basic statistics, graph analysis of data, hypotheses test, Chi-Square test, Regression analysis and FMEA.
     
Improve (I):
 
In this phase it takes the action over the process to improve it based on the sources of variation (X´s) identified during Analyze phase (A). At the end of this phase, it should be evaluated the new sigma capability of the process (?), to prove that happened significant improvement.
The main tools used are: Action Plans, FMEA, Design of Experiments and Regression Analysis.

Control (C):
 
This is the last step. At this point it should be put to work approaches to monitor the sources of variation (X´s) identified to keep the new capability achieved. It should be passed the accountability by monitoring the process to its owners.
One confirmation of the economical benefits achieved should be done. The main tools used are: Control charts, Mistake Proofing Devices (Pokayoke), Control Plans, Procedures etc.

SIX SIGMA METHODOLOGY - DFSS

As for Six Sigma – DMAIC, the methodology DFSS (Design for Six Sigma) is a structured and disciplined approach to assure that new processes, services or products to be launched with efficiency level close to 6.
There are five steps:

Define (D):
To define the Project to be developed and to identify the associated risks. Moving management.

Measure (M):
To identify the customers and its needs and to translate its needs in requirements of projects.

Analyze (A):
To develop concepts of design and to link outputs and inputs of the process, as well as to pick up the Best design.

Design (D):
To develop high level design, to develop the detailed design and to prepare the pilot plan.

Verify (V):
To conduct the pilot and to implement the new design. To pass the process to the process owner.

LEAN SIX SIGMA METHODOLOGY

It links to the Six Sigma DMAIC methodology the easiness, speed and versatility of Lean, promoting a business system to organize and manage the product developments, operations and services. Many businesses utilize the Lean Six Sigma principles, practices and tools to obtain goods and services with more quality, reducing dramatically the costs and optimizing the use of its resources.

For each step of the Six Sigma DMAIC are introduced Lean tools, in a manner that one part of the team use the speed and easiness of the Lean to act over the process conditions where, basically, what should be done is “roll up their sleeves and attack the process” and give fast answers to the organization. In the meantime, other part of the team works on the deeper statistic analysis using the science and discipline of the Six Sigma Methodology.