DPPM sample size calculator
Given a certain number of known failures and your sample size, the DPPM calculator can give you the estimated defective parts per million (DPPM) with a certain degree of confidence. Typical value for confidence level is 60 percent.
Purpose
For a specified Chi-square confidence level, observed or assumed number of fails and Sample size, the calculator provides failure fraction expressed in terms of 'defective parts per million'.
Equation
\[\begin{aligned} \mathbf{DPPM} = 10^6 * \frac{ \mathbf{CHISQ.INV} ( {\mathbf{CL}, 2* \mathbf{fails} + 2}) }{2 * SS} \\ \end{aligned} \]
DPPM - Defective Parts per million
CL - Confidence Level represented as a decimal
SS - Sample size
Fails - Number of failures in your sample size
Important Limitations on Use of Data
TI provides this data for your convenience. However, there are significant limitations of its usefulness as an indicator of how TI parts (including related software) may perform when used in various applications.
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