Before revision: Quantitative analysis techniques, such as Fault Tree Analysis (FTA, which had been in use by the nuclear industry), Quantified Risk Assessment (QRA, also referred to as Quantitative Risk Analysis), and Layer of Protection Analysis (LOPA) also began to be used in the process industries in the 1970s, 1980s and 1990s.
After revision: Quantitative analysis techniques, such as Fault Tree Analysis (FTA, which had been in use by the nuclear industry), Quantified Risk Assessment (QRA, also referred to as Quantitative Risk Analysis), and Layers of protection analysis (LOPA) also began to be used in the process industries in the 1970s, 1980s and 1990s.