Statistical Sample Size

Sample size determination is the act of choosing the number of observations or replicates to be included in a statistical sample. Frequently asked questions are:

  • Which are the basic requirements in a sample size determination for variables and attributes?
  • How can I determine the minimum sample size for CPk calculations?
  • What is the minimum sample size for validations using the Binomial approach for a specific level of confidence and % of conformance?
  • What are the sample size requirements for Confidence Intervals on population parameters?
  • What are sample size requirements for Tolerance Intervals?

WHO SHOULD ATTEND

Managers, Supervisors, Engineers, and Team Leaders from the Quality functional areas.

BENEFITS

Be absolutely certain to determine the minimum sample size for all manufacturing process applications, assuring regulatory compliance with a level of confidence at the minimum cost.

TRAINING TOPICS:

Introduction

Statistical Distributions Review

  • Hypergeometric
  • Binomial and Negative Binomial
  • Poisson
  • Normal
  • Weibull
  • Cpk and Ppk Capability Analysis
  • Basic Requirements in Sample Size Determination
  • OQ and PQ Considerations for Sample Size Determination 
  • Define Risk Assessment / Importance Level
Sample Size for Attribute Data Type
  • Sample Size to Binomial c = 0, % of Confidence and % of Conformance
  • Sample Size to Estimate a Binomial Proportion
  • Sample Size to Estimate a Poisson Occurrence Rate
Sample Size for Variable Data Type

Sample Size for a Confidence Interval

  • Population Average (Normal Distribution)
    • When σ is assumed to be known
    • When σ is assumed to be Unknown
  • Population Average (Weibull Distribution)
    • When α and β values are used to approximate the Normal Distribution
  • Reliability Demonstration
    • Three parameter Weibull Distribution
    • Two-parameter Weibull Distribution
    • Standard Weibull Distribution
    • Mean of two Parameters
    • Variance of two parameters
  • Sample Size for Tolerance Intervals
  • Sample Size to perform Process Capabilities