ProSIS-FSE developed an easy to use FREE Safety Integrity Level (SIL) verification tool that utilizes Fault Tree Analysis. Unlike most FTA tools on the market, ProSIS-FSE’s SILCalc created a simple and easy to use user interface. The calculation engine uses complex pre-built fault trees. The fully functional Web based tool is available to use for free with limited usage.  Unlimited usage is available for a fee.