Conducting the Knowledge Transfer
February 12, 2025
The global economic crisis that started in 2008 has engulfed the entire world and has laid waste to the process of globalization that was blamed by many as being the root cause of the crisis. After the American Investment Bank, Lehmann Brothers filed for Bankruptcy in September 2008, the entire global financial system was at […]
The Emergence of the Internet and the High Hopes that accompanied it For those of you old enough to remember the emergence of the internet in the 1990s, you would have no doubt been taken in by the then prevailing optimism and hope about the medium finally ushering in an egalitarian and a just world. […]
Many governments all over the world have made attempts to abolish poverty. However, most of them have not succeeded. The theme of eradicating poverty has been common to both socialists as well as capitalists. However, no one seems to have been able to solve the problem. It is likely that the problem itself has been […]
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 […]
Incompatibility Creates Problems Developments in IT have created more problems than solutions because of the “incompatibility” among the various parts of the supply chain. Information becomes knowledge only when the means to process it is in place and the process does not “distort” the message. Like garbled voices coming over crackling phones in yesteryears, unless […]
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.
Your email address will not be published. Required fields are marked *