Some Golden Rules in improving Reliability:

Golden rules of improving reliability are

  1. Summation of all stress and strains must be < than the strength, stiffness and resilience of the system to eliminate early, repetitive or infant failures. This addresses 3 to 5% of all failures in a system
  2. Balance all interactions to eliminate all random failures. This addresses 80 to 90% of all failures in a system
  3. Improve wear resistance and prevent accelerated deterioration to prolong life and eliminate all wear out failures. This addresses 5 to 7% of all failures in the system
  4. Think in systems and Baysian Probability to anticipate, monitor and eliminate all failures

Classification of Failure Modes of an engineered system:

  1. Early Failure Modes — due to stress, strain, pressure, flow, thermal gradients — 3 to 5% of all failures
  2. Random Failure Modes — related to interactions, balance and feedback loops — 80 to 90% of all failures
  3. Wear Out Failure Modes — due to tribological imperfections of surfaces, interfaces and materials — 5 to 7% of all failures

Basic Theorems

  1. Machines are complex systems with hidden imperfections.
  2. Higher the interactions; more are the feedback loops and more are the chances of random failures
  3. Small changes create dramatic changes in the output, performance quality and failures
  4. Right Interactions of opposites play a vital role in maintaining the integrity and reliability of an engineered system
  5. Improvement can only be done by continually negating the imperfections hidden in the interdependent interactions

Steps of the Reliability Improvement Process:

  1. Improve Inherent Reliability by eliminating failures (Analysis)
  2. Avoid Consequences of Failures (Planning)
  3. Maintain a system based on conditional probability of a failure hidden in the interactions (Algorithms)
  4. Prevent accelerated deterioration (Engineering actions and practices)
  5. Draw up a superior specification for the next engineered system to be procured.