Robot Advisors in Asia
The integration of cutting-edge technology with financial services has resulted in several innovative methods and tools which use sophisticated technology to serve potential clients better. One such innovation in financial services is the use of Robot Advisors or Automated Software also known as Bots to connect retail customers with the financial institutions. Worldwide, there has […]
HR Metrics and Workforce Analysis
HR Metrics and Workforce analysis is a useful strategic tool for HR which shares information and evidences about the functioning of the entire system by relying on facts and figures, as opposed to mere assumptions or personal opinions. Over a period of time, the HR Metrics has evolved with the usage of more quantitative and […]
Change and Risk Management in ERP Implementation
An ERP system is a process and not an end in itself. Perfunctory Implementing of ERP system will not boost efficiency. Reasons for failure of an ERP project such as lack of commitment from management and employees, lack of communication, knowledgeable employees not available for the project, are mostly organizational issues and have nothing to […]
Supply Chains as Sources of Competitive Advantage
Optimizing the Supply Chains A supply chain is the network of relationships between the upstream and downstream activities with all stakeholders who are involved in this chain of relationships. To take an example, if a particular good or service has to be delivered to the customer, there are raw materials that are needed for the […]
Integrated Product and Process Development – Meaning, Advantages and Key Factors
Introduction Objective of any organization is to provide customer satisfaction by building product and services, which not only satisfy needs and want but also create value for them. This requires product design based on the customer feedback and production process which not only minimizes cost but also provides a competitive advantage. However, most organizations tend […]
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
