Template:Statistical tests for effectiveness of corrective actions crow rga

Introduction
The purpose of the statistical tests is to explore the effectiveness of corrective actions during or at the end of a phase. Say we have two phases, Phase 1 and Phase 2. Suppose that corrective actions are incorporated during or at the end of Phase 1. The system is then operated during Phase 2. The general question is whether or not the corrective actions have been effective. There are two questions that can be addressed regarding the effectiveness of the corrective actions: Question 1. Is the average failure intensity for Phase 2 statistically less than the average failure intensity for Phase1? Question 2. Is the average failure intensity for Phase 2 statistically less than the Crow-AMSAA (NHPP) instantaneous failure intensity at the end of Phase 1?