MSG Team's other articles

9232 Evaluation and Selection of ERP Packages

Evaluation and selection of ERP package is an essential criterion for successful ERP implementation. Quality of selection will have a long term impact on the processes of the organization. It is also not easy to switch to another product with concomitant scale of investment and complexities. This evaluation and selection process should be properly directed […]

10619 The Need for Person Independence in Software Project Management

The Perils of Person Dependence Imagine you are a project manager of a software project and are managing multiple resources. If by chance, one of your employees has an emergency (personal or otherwise) and has to take leave suddenly, your first priority should be to ensure that the employee gets time off and next, you […]

11740 Users Interface and Users Management in ERP System

Users interface directly impact usability of an ERP system. A properly designed user interface provides proper accessibility to the intended functions of the system and enables execution of transactions. Earlier users accessed the system with dumb terminals (ASCII) which had lot of usability deficiencies and this led to subsequent adoption of Graphical Users Interface (often […]

12753 Step 3A: Choosing the Correct Control Chart (Discrete Data)

If the data type that needs to be charted is discrete, then it must fall between one of binary or count types. As the name suggests in case of binary distribution, there are only two possibilities, success and failure, defective and not defective, whereas in the case of count type distribution there may be more […]

11087 Role of Derivatives in Causing the Global Financial Crisis

The previous articles in the module have discussed how the global financial crisis has been caused due to a combination of factors starting with the collapse of the housing market in the US and then due to the integration of the global economy rapidly spread to other parts of the world. An aspect that was […]

Search with tags

  • No tags available.

What Is Sigma ?

Sigma or standard deviation is a statistical measure of dispersion in data. It is a measure which uses the characteristic of past data to make judgements about how the process will perform in the future. If a given set of data has normal probability distribution then the number of defects that will occur in the process over a period of time can be known depending upon the sigma level of the process.

What Are Sigma Levels ?

The sigma (standard deviation) is multiplied with the numbers 1, 2, 3 etc to come up with a range. For example lets assume that the average of a data set is 10, while the sigma is 2. Hence 1 sigma will include all the data points between 10 +/-2 i.e. between 8 and 12. A 2 sigma measure would include 10+/-2(2) i.e. all data points between 6 and 14. So on and so forth.

However, it is a known fact that in a normal distribution the points tend to be around the mean. Therefore all the points will be closer to the average. Hence as one goes to farther and farther sigma levels the additional gains in terms of productivity are less.

Observations

  • Sigma levels which are less than 3 are not desirable. Companies with less than 3 sigma levels will not be able to survive in a competitive marketplace.
  • After Sigma Level 3 the gains are very small. But these gains make a considerable difference to the overall cost of quality as explained in costs of poorly performing processes.

To be a six sigma organization, the processes of an organization must be able to support this kind of efficiency sustainably. Building such robust processes requires a lot of intelligence and effort.

Sigma LevelDefects/MillionPercentage Defects
169146269%
230853831%
3668076.7%
462100.62%
52330.023%
63.40.00034%
70.0190.0000019%

Article Written by

MSG Team

An insightful writer passionate about sharing expertise, trends, and tips, dedicated to inspiring and informing readers through engaging and thoughtful content.

Leave a reply

Your email address will not be published. Required fields are marked *

Related Articles

The Cost of Poorly Performing Processes – Need for Six Sigma

MSG Team

What is Six Sigma ? – A Tool to Conquer Variability

MSG Team

What Six Sigma is Not ? – Fallacies about Six Sigma

MSG Team