The New Economics of the Music Industry
The economics of the music industry has been radically changed in the past two decades or so. Ever since the internet became a reality, music could be shared for free. The entire industry faced the onslaught of the latest developments in web technology. Companies like Napster encouraged piracy and allowed users to download and share […]
The Opportunities and Challenges of Project Management in Virtual Workplaces
Why Project Managers Might Find Managing Remote Teams Challenging As workplaces became virtual and employees started working from home due to the Covid 19 Pandemic, organizations found that there are many challenges in managing such virtual workforces. For instance, Project Management is challenging when managers cannot meet employees face to face and instead, have to […]
Employee Portal for Human Resource
Introduction Information systems have revolutionized the way businesses get conducted. It facilitates automation across departments. Information systems are getting actively used by human-resource team. Most of Human-Resource activities are done through online or web-based portals. This web based portal help employee or HR team member access data from anywhere in the world or from remote […]
International Trade Integration
No doubt international trade has existed spanning civilizations, in the current global economic situation no country can keep away without participating in international trade. Countries are moving cautiously away from capitalistic and protectionist outlook and engaging in trade with other countries. With the creation of WTO, there have been constant efforts made to unite countries […]
History of International Trade
Any time you walk into a super market and pick up any stuff like a knife or a toy and chances are that the item has been manufactured in China or assembled in Mexico. Pick up coffee pods and you will see that they have been imported from Africa. When you shop for clothes, it […]
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
