Complementing LOPA with Economics

摘要

Layer of Protection Analysis (LOPA) is a simple and successful method to design protection systems for chemical process plants. In this paper we propose methods to complement LOPA to economically optimize such protection systems and to compare alternative systems based on their expected life-cycle costs and benefits. We propose three methods: a simple method that calculates the expected annual losses (in economic terms) due to failure of protection; a more complicated one, that takes into account the total life-cycle cost and economic losses from spurious demand of protection layers; and a method that calculates the Net Present Value of alternatives.