Value Chain and E-Strategy – Components of Commercial Value Chain
Introduction All companies undertake series of activities in order to deliver a product to the customers. These series of activities like procurement of raw material, storage, production, distribution, etc. are referred as value chain activities. The function of value chain activities is to add value to product at every stage before it is delivered to […]
Are Indian Start-ups and eCommerce Firms Living in Fantasy Land without Profits?
Are Indian Start-ups and eCommerce Firms Living in Fantasy Land? It is a well known fact that India is a favourite destination for yield hungry investors and angel investors keen to fund start-ups and eCommerce firms in the hope that they would be able to garner significant profits at a later stage. Indeed, India is […]
The New Trend: Insourcing IT Services
Insourcing is the opposite of outsourcing! Well, that sounds obvious, isn’t it? However, many people do not know what it means. However, this is a trend that is hitting the market in developing countries. Take India for instance; it is the largest exporter of software services in the world. A few bellwether companies primarily ran […]
Importance of Project Management for Organizations
Project management is the art of managing the project and its deliverables with a view to produce finished products or service. There are many ways in which a project can be carried out and the way in which it is executed is project management. Project management includes: identifying requirements, establishing clear and achievable objectives, balancing […]
The Shock of Gray and Its Implications for the Healthcare Sector
What is meant by the Shock of Gray and its Implications? The Shock of Gray is a term used to describe the ageing of the populations in the West with the retirement of the Baby Boomer generation and the resultant “graying” of the western societies. This phenomenon has several economic implications mainly related to the […]
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 than two possibilities of the process, the number of defects still need to be counted. The difference between the two is subtle. However, given the fact that there are fixed rules governing when which chart needs to be used, the confusion is reduced.
Equal Subgroup Size: In this case, the Six Sigma process methodology suggests using the C Chart. The C Chart counts the number of defects that are happening per unit of unit. This could be per minute, per hour, per day or per week and so on. The important part here is that since the time period is fixed, so is the sample size. The C Chart will tell you how many observations from a given sample failed to meet the criteria specified by the control limits.
Unequal Subgroup Size: In this case, the Six Sigma process methodology recommends using the “U” chart. The U chart counts the rate of defects. This means that it keeps a track of the number of units that it has monitored and how many have failed the given criteria specified by the control limits. The U Chart will tell you, for example that 5/1253 units have failed to comply. Hence it does not require a fixed time period or a fixed sample size and may be more convenient to use.
Equal Subgroup Size: In this case, the Six Sigma process methodology recommends using the NP Chart. The NP chart also counts the number of defects per period of time just like the C Chart. There is however a subtle difference between the two. C Chart is used when the occurrence of defects is rare. However, NP chart uses the binomial distribution. Therefore, the occurrences do not have to be rare. As a thumb rule, if there is a chance more than 5% defects in a process, then the NP chart must be used.
Unequal Subgroup Size: In this case, the P chart is recommended. Once again, it is quite similar to the U chart. This chart calculates the defects as a percentage figure meaning that it takes into account the units that have gone through the process just like the U Chart. The U chart also uses the Binomial distribution and is used when the occurrences of defects is not rare.
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Step 3B: Choosing the Correct Control Chart (Continuous Data)
February 12, 2025
