Reliability theory is a critical aspect of engineering and mathematical analysis. Simply put, it refers to the probability that a system will work as intended for a given period. Many synonyms can be used for this term, depending on the context of the discussion. Some of these synonyms include reliability analysis, reliability engineering, failure mode analysis, and failure analysis. Other synonyms may be dependability or resilience analysis, system safety analysis, or hazard analysis. Regardless of the term used, reliability theory plays a crucial role in many fields, including aerospace, electronics, and manufacturing industries, ensuring that systems and processes maintain performance and accuracy over time.