When customers give specifications, when factories trial produce products or when R&D personnel design products, formulas are often used to calculate yields. When there are many parameters for product characteristics or factory machine monitoring, it is not only time-consuming and labor-intensive to confirm defective products, but also the specifications every time. Adjustments will involve the modification of formulas, and as long as there are related projects, it will take a lot of effort to do the preparatory work repeatedly. Therefore, this topic focuses on the calculation of yield and the setting of related specifications, including how to make appropriate modifications to subsequent specifications.
how to JMP Set yield specifications ?
First of all, when it comes to yield, the first thing you must have is specifications. At the beginning of this article, we will introduce how to set specifications. JMP Specification settings can be set for a single parameter or multiple parameters, and can be added after setting. column property , I will explain to you two situations below:
Situation 1. Single parameter setting specification
As shown in Figure 1 and Figure 2, right-click on any parameter field and select Spec Limits under Column Properties to add specifications and display them on the graph.
picture 1
figure 2
Situation 2. Multi-parameter setting specifications
exist Analyze>Quality and Process>Manage Spec Limits Down ( picture 3) , multiple parameters can be specified and added at one time Column Properties(Save to Column Properties) , you can also save the specifications as a data sheet for future reading. ( picture 4) , in addition to manual input, you can also copy and paste the upper or lower limits of multiple parameters in sequence.
picture 3
Figure 4
How to calculate yield ? Easily set up defect rate summary table
The second part I want to explain to you is how to calculate the yield, use Analyze>Distribution , if the specifications have been set, in Nonconformance Down ( picture 5) It can automatically display the defective rate and the expected expected value of the estimated defective rate. However, in general, how to integrate the defective rate results of many parameters is also a problem that users often encounter. Here JMP Provides a useful tip on Nonconformance Right-click on the table and select Make Combined Data Table( picture 6) , you can directly generate a summary table of defective rates ( picture 7)
picture 5
Figure 6
Figure 7
If you encounter appearance judgment Pass/Fail Nominal data type ( picture 8) How to calculate the defective rate? Here is another one JMP Function, Analyze>Tabulate( picture 9) , drag the relevant variables to the relevant fields, and match them with the red drop-down menu Make Into Data Table( picture 10) , generate defective rate and yield statistical tables ( picture 11)
Figure 8
Figure 9
Figure 10
Figure 11
Determine the impact of adjusting specifications on defective rate
3rd Letâs talk about this part Based on the existing data distribution, adjust the specification boundaries or understand the impact of specification adjustment on the defective rate , the first step is to confirm the data distribution. If it is a continuous variable, click on the red drop-down menu under this parameter. Continuous Fit , then select Fit All ,let JMP Automatically fit the best-fitting distribution ( picture 12) , if the data belongs to normal distribution, you can choose Interactive Capability Plot( picture 13) Dynamically adjust the upper and lower limits to understand changes in the expected defective rate under normal distribution ( picture 14) ,
Figure 12
Figure 13
picture 14
In addition, in the drop-down menu of fitting normal distribution, you can choose Process Capability ( picture 15) , you can enter the probability values of the upper and lower cutoff points based on the data distribution or calculate the specifications based on the standard deviation. ( picture 16) , it should be noted here that some distributions cannot be used, such as Cauchy, Student t Or a discrete probability distribution.
Figure 15
Figure 16-1 Compute specifications based on quantile probabilities
(Figure 16-2) Calculate specifications based on standard deviation multiples
After the specifications are calculated, the relevant process capabilities, histograms and defective rate data will be displayed (Figure 17), and the adjusted specifications can be saved as Column Property (Figure 18)
Figure 17
Figure 18
The above is the operation process of establishing specifications and adjusting specifications to confirm the defective rate. Users mostly use the specification setting function in the first half, and then want to further adjust the specifications based on the collected samples and their distribution, and at the same time understand that the defective rate changes less. Understand, through the explanation of this article, users in need can control and design products more time-saving and efficient. welcome try out JMP30 sky , to help you quickly complete your daily analysis work.
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