Six Sigma is a business management strategy originally developed by Motorola, USA in 1981. Bill Smith first formulated the particulars of the methodology at Motorola in 1986. Nowadays it has spread in many sectors of industry. Six Sigma seeks to improve the quality of process outputs by identifying and removing the causes of defects (errors) and minimizing variability in manufacturing and business processes. It uses a set of quality methods, including statistical methods, and creates a special infrastructure of people within the organization ("Black Belts", "Green Belts", etc.) who are experts in these methods.Six Sigma originated as a set of practices designed to improve manufacturing processes and eliminate defects, but its application was subsequently extended to other types of business processes as well. In Six Sigma, a defect is defined as any process output that does not meet customer specifications, or that could lead to creating an output that does not meet customer specifications

Six Sigma was heavily inspired by six preceding decades of quality improvement methodologies such as quality control, TQM, and Zero Defects, based on the work of pioneers such as Shewhart, Deming, Juran, Ishikawa, Taguchi and others.

Six Sigma at many organizations simply means a measure of quality that strives for near perfection. Six Sigma is a disciplined, data-driven approach and methodology for eliminating defects (driving towards six standard deviations between the mean and the nearest specification limit) in any process -- from manufacturing to transactional and from product to service.The statistical representation of Six Sigma describes quantitatively how a process is performing. To achieve Six Sigma, the rate of the defects in a process should not exceed beyond the 3.4 defects per million opportunities(3.4 DPMO) or 99.99966% efficient.

six sigma processThe term "six sigma process" comes from the notion that if one has six standard deviations between the process mean and the nearest specification limit, as shown in the graph, practically no items will fail to meet specifications. This is based on the calculation method employed in process capability studies.Capability studies measure the number of standard deviations between the process mean and the nearest specification limit in sigma units. As process standard deviation goes up, or the mean of the process moves away from the center of the tolerance, fewer standard deviations will fit between the mean and the nearest specification limit, decreasing the sigma number and increasing the likelihood of items outside specification.

Graph of the normal distribution, which underlies the statistical assumptions of the Six Sigma model. The Greek letter σ (sigma) marks the

distance on the horizontal axis between the mean, µ, and the curve's inflection point, in this case σ=1. The distance is equally distributed

horzontally to both sides of the mean µ as: [µ - σ/2, µ + σ/2]. The greater this distance, the greater is the spread of values encountered. For

the curve shown above, µ = 0 and σ = 1. The upper and lower specification limits (USL, LSL) are at a distance of 6σ from the mean. Because of

the properties of the normal distribution, values lying that far away from the mean are extremely unlikely. Even if the mean were to move

right or left by 1.5σ at some point in the future (1.5 sigma shift), there is still a good safety cushion. This is why Six Sigma aims to have

processes where the mean is at least 6σ away from the nearest specification limit.

The table below gives long-term DPMO values corresponding to various short-term sigma levels

Sigma level DPMO Percent defective Percentage yield Short-term Cpk Long-term Cpk

1 691,462 69% 31% 0.33 –0.17

2 308,538 31% 69% 0.67 0.17

3 66,807 6.7% 93.3% 1.00 0.5

4 6,210 0.62% 99.38% 1.33 0.83

5 233 0.023% 99.977% 1.67 1.17

6 3.4 0.00034% 99.99966% 2.00 1.5

7 0.019 0.0000019% 99.9999981% 2.33 1.83

Kaizen

Kaizen is a Japanese word for "improvement" this philosophy focus on never-ending efforts for improvement in manufacturing activities, business activities in general, and even life in general, depending on interpretation and usage. When used in the business sense and applied to the workplace, kaizen typically refers to activities that continually improve all functions of a business, from manufacturing to management and from the CEO to the assembly line workers.By improving standardized activities and processes, kaizen aims to eliminate waste.Kaizen is a daily activity, the purpose of which goes beyond simple productivity improvement. It is also a process that, when done correctly, humanizes the workplace, eliminates overly hard work, and teaches people how to perform experiments on their work using the scientific method and how to learn to spot and eliminate waste in business processes.

The kaizen method consists of 5 elements:1. teamwork2. personal discipline3. improved morale4. quality circles5. suggestions for improvement

On analyzing the definition, we find that there are two basic ingredients of kaizen. Absence of any one of them can never be turned as kaizen. The two ingredients are:

Improvement Continuity

The kaizen philosophy believes on improvement that is constant. It stresses that small improvement on a continuous basis can bring monstrous change.

Pizza Hut implement kaizen method, they concentrate on standardizing best practice in work area. Allow their employees to participate in the development of standards. As they are a valuable but often overlooked source of information.