Champions and sponsors
Champions are persons amongst the top-management who understand Six Sigma and are committed to its success. They may, typically, be a business unit head who initiates the Six Sigma projects in their unit. As they understand the business, they would be most suited for selecting Six Sigma projects and ensuring their implementation and success.

Sponsors are the owners of processes and systems who, under the guidance of champions, help initiate and co-ordinate Six Sigma improvement activities in their areas of responsibility.

Experts
The day-to-day Six Sigma programme is managed by three levels of experts - the master black belt, the black belt and the green belt. They are the full time catalysts or change agents.

Master black belts are the most proficient persons in the team. Being experts in statistical and implementation techniques, they help champions to structure and co-ordinate projects. They provide the technical and day-to-day organisational leadership to the whole programme. They also train new black belts. Apart from possessing technical expertise, master black belts also need to be effective communicators and teachers.

Black belts are technical leaders that create and lead teams implementing Six Sigma. They must be experts in basic statistical tools and also possess strong management and communication skills. As agents of change, they must be able to think creatively and challenge conventional methods. They should be actively involved in the process of organisational change.

Green belts are individual project leaders who form and manage Six Sigma projects. These could be department heads. Trained in project management, quality control and problem solving, they help to incorporate Six Sigma methods into daily operations. They provide basic process knowledge and assist black belts in collecting and analysing data. They are not, however, employed full-time in the Six Sigma programme.

The Six Sigma programme can be managed by a small team of full-time personnel. A business unit with around 1,000 employees would generally need one master black belt, who would be assisted by a team of around eight to 10 black belts. Each black belt would complete about five to seven projects per year. Project teams are led by green belts. All the members of the team have a well-defined role with measurable objectives.

The training and infrastructure (computers, statistical software, etc) require a fair amount of investment. The top management must appreciate the value of this investment and give it their whole-hearted support.

The implementation strategy
The steps required to successfully implement Six Sigma are broadly:

Top management training
As mentioned earlier, Six Sigma is an enterprise-wide programme. It is usually effective only if implemented 'top-down'. Therefore, the Six Sigma programme should ideally begin with the training of the CEO and the senior management.

The idea of this training is to:

Only if the top management is fully conversant with the nuances of the programme can they ensure a successful implementation through their staff. Only if they are aware of the work involved, can they sanction the large budgets required in the initial stages of the programme.

The first stage also involves taking up a few representative projects to demonstrate the effectiveness of programme. It is important that these projects / processes are cross-functional and have some easily identifiable improvement parameters.

Strategic planning
Having familiarised itself with the programme, the senior management gets down to the business of setting up necessary infrastructure to support the Six Sigma programme, and sets up the steering committee. Employees who would be full-time in-charge - the master black belt and black belts - are identified and imparted the necessary training. All employees are put through an orientation programme.

The senior management must also spread awareness about the programme the concerned departments. An environment of innovation and creativity needs to be fostered. Policies and procedures regarding process selection, implementing improvements, rewarding success, not punishing failure, etc, have to decided and communicated.

Systems need to be developed to properly capture and integrate information, data and inputs that would flow from customers, employees, suppliers, etc.

Processes
With the entire infrastructure in place, the programme of process selection and improvement can start. The process selection team should be cross-functional, and also involve the owners of the processes. The processes selected should offer tangible benefits to the customers and be in line with the company's business strategy.

Six Sigma projects are conducted by small teams, led by green belts and assisted by black belts.

The improvement measures are identified and implemented. Regular tracking of the progress is essential, to prevent a waste of time, effort and money on non-viable solutions and to ensure the selection of measures which have large and long-term benefits.

Part of the system
Six Sigma should become a habit, a part of the system, an integral part of the organisational culture. A framework for continuous process improvement is established. All departments are actively involved. While some departments will identify and improve processes, other can assist and support them in this endeavour. For example finance will tracks costs and benefits, HR will communicate, IT will set up necessary systems, sales will gather customer feedback, etc.

This approach is simple, but not easy. But the results justify the efforts. It is seen that companies that have successfully implemented Six Sigma have performed better in virtually every business category, including return on sales, return on investment, employment growth, and share price increase.

Statistical tools help to derive useful information from the huge amount of data and help deal with process variations more effectively. The toolkit is diverse and flexible, and can be relatively sophisticated. Availability of user-friendly statistical software enables effective and broad utilisation of the statistical tools.

Some of the common statistical tools used in Six Sigma are discussed below.

Gauge repeatability and reproducibility studies help to estimate the contribution of variation attributable to the measurement system itself. They assess whether measurement processes and equipment produce consistent and accurate results. If these estimates indicate that the recorded measurements may be unreliable, this may impact all subsequent analyses. Without such studies, satisfactory parts might be rejected and unsatisfactory parts accepted.

Failure modes and effects analysis is used to identify potential failure modes of a product, the causes and effects of such failure, and possible solutions to reduce or eliminate them. During the design stage, it helps analyse and correct potential reliability problems.

Control charts display the results of a process over time. They are used to ensure that essential product characteristics remain constant over time and to determine the need for any process adjustment. Periodic sample measurements are plotted against the mean to check for any noticeable process shifts with time.

Process mapping. A process is defined as a series of connected steps or actions to achieve a desired outcome. A process map is a visual aid or a diagrammatic presentation of the work process, which shows how inputs, outputs and tasks are linked. It is one of the most effective ways of gaining an understanding of existing processes

Variance components analysis looks at different sources of variability and helps assess where the variations in product quality are occurring. It estimates the amount of variance attributable to the inputs separately. Isolating product variability problems is particularly critical to quality assurance, and provides insight into the sources of variability.

Pareto analysis is based on the principle that 'not all of the causes of a particular phenomenon occur with the same frequency or with the same impact'. Such uneven distribution of quality defects is very common and can easily be detected through a Pareto chart. This kind of analysis facilitates prioritisation and targeting these 'major causes' for cost-effective quality improvement.

Capability analysis. Process capability is a measure of the repeatability of a process. This information helps determine the proportion of output that will be acceptable. This tool assists in the maintenance of suitable product specifications. Such analyses can help evaluate both short-term and long-term variability.

Cause-and-effect matrix is also known as a fishbone or Ishikawa diagram. It is a brainstorming tool used for determining root-cause hypotheses and ascertaining potential causes (the bones of the fish) for a specific effect (the head of the fish).

Measurement system analysis aims at standardising the methods of analysis to ensure reliability and authenticity of the measuring systems. It is an experimental and mathematical method of determining how much the variation within the measurement process contributes to the overall process variability. It checks the bias, linearity, stability, repeatability and reproducibility of the measuring system.

Accelerated life tests help evaluate product life cycles and are particularly useful to test products designed to last for a long time. The estimate of the failure time distribution of products provides information about expected reliability in a short period of time, by accelerating the real-life conditions. Such tests are also good for finding dominant failure mechanisms.

Design of experiments is a structured method for determining the relationship between the factors affecting a process and the output of that process. It involves conducting controlled experiments and statistically evaluating the observations to determine how each input factor influences the output.

In the last article in the series, we will look at how Six Sigma is being employed in non-manufacturing situations and how it compares with other quality improvement tools.