What is Your SIS Doing When You're Not Watching?

    What is your SIS doing when you're not watching?

    You pay a lot of money for your Safety Instrumented System (SIS) and spend a lot on its upkeep. You expect it to always be there for you. Are you really getting your money’s worth? Is it doing things you don’t know about, or not doing things it should?  In this paper, we examine many of the necessary administrative tasks associated with managing Independent Protection Layers (IPLs) with particular emphasis on SIS. Some of these tasks are often overlooked, and significant risks exist if they are not done properly.