DATA ANALYSIS AND QUALITY CONTROL: TOP 6 STATISTICAL TOOL USED IN QUALITY CONTROL

 The most common statistical techniques used in quality control include:

1. Statistical Process Control (SPC): 

SPC is a method of monitoring and controlling a process to ensure it is operating within specified limits. It involves collecting data on a process and using statistical tools to analyze the data and identify patterns or special causes of variation. SPC charts, such as control charts, are used to graphically display the process data and identify when a process is out of control.

2. Control Charts: 

Control charts are a type of SPC chart that is used to monitor process data over time. They are used to identify patterns or special causes of variation in a process, such as shifts in the mean or changes in the spread of the data. Common types of control charts include X-bar and R-charts, which are used to monitor the mean and variability of a process, respectively.

3. Pareto Charts: 

Pareto charts are used to identify the most common sources of defects or problems in a process. They are a type of histogram that is sorted in descending order, with the most frequent problem at the left side of the chart. They are named after Vilfredo Pareto, an Italian economist, who observed that 80% of the effects come from 20% of the causes, this is known as the Pareto principle.

4. Histograms: 

Histograms are used to display the distribution of a process variable. They are a graphical representation of the frequency of occurrence of different values in a dataset. Histograms are useful for identifying patterns or trends in the data, such as the presence of outliers or skewness in the distribution.

5. Capability Analysis: 

Capability analysis is used to determine if a process is capable of meeting customer requirements. It involves comparing the process performance to the customer's specifications and determining if the process is capable of consistently producing products that meet those specifications. Capability analysis is typically performed using statistical tools such as process capability indices (Cp, Cpk, Pp, Ppk)

6. Design of Experiments (DOE): 

The design of experiments is a systematic method of testing the relationship between variables and determining which variables have the greatest effect on the outcome of a process. It is used to identify the most important factors that affect the quality of a product or process and to determine the optimal settings for those factors. DOE uses statistical techniques such as analysis of variance (ANOVA) to analyze the data and identify the most important factors.