Pharmaceutical companies at every stage are too concerned about quality aspects of their product and key to maintaining an improving quality is systematic use of data, in place of intuitions or anecdotes. Pareto charts are bar graphs with the bars ordered by height. They are often used to isolate the “vital few” categories on which we should focus our attention.
In statistical quality control, p-chart is a kind of control chart used to track the proportion of nonconforming units in a sample. Sample proportion nonconforming can be explained as the ratio of number of nonconforming units to the sample size.
The p-chart only accommodates "pass"/"fail"-type inspection as determined by one or more tests, effectively applying the specifications to the data before they are plotted on the chart.
Sampling requires some careful consideration. If the organization elects to use 100% process inspection, the production rate determines an appropriate sampling rate which in turn determines the sample size.If the organization elects to only inspect a fraction of units produced, the sample size should be chosen large enough so that the chance of finding at least one nonconforming unit in a sample is high—otherwise the false alarm rate is too high.
A method can be to fix sample size so as there is a 50% chance of detecting a process shift of a given amount (for example, from 2% defective to 4% defective)
For Instance: A production manager has inspected the number of defective tablets in five random samples with 20 tablets in each sample. The number of defective tablets in each sample of 20 tires can be used to Calculate the control limits, i.e., add all the proportions of defectives (in percentage) to get CONTROL LIMIT (CL). Then calculate standard deviation, and get to Upper Control Limit (UCL) and Lower control limit (LCL). Plot a graph with fraction defective (on Y-axis) vs Sample number (X-axis). This way you will be able to stastically control the production quality that can be applicable to the quality process arriving at desirable end product quality.
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Thank you. So, The sample taken for inspection of defects must be high to get higher three standard deviation (3S). If the sample size is small, higher 3S and LCL in minus value will be present. Pareto chart is an important statistical quality control for quality attributes. It allows the manufacturer to determine if quality of its drug products during manufacture or for different batches has the same quality or not.
You got it! Not only product put this as well to control process quality, which would lead to quality end product.
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