SIL solutions are certainly not always the most cost-effective solutions for decreasing process risk. Many times, IMPLEMENTING a SIL SOLUTION will require increased equipment, which inevitably will require increased maintenance. Additionally, it is likely that the higher the SIL LEVEL, the more frequent the proof TESTING interval will be, which may ultimately increase the amount of system maintenance that is required. This is why the standards recommend a SIL based solution only when process risk cannot be reduced by other methods, as determined by LOPA.

SIL solutions are certainly not always the most cost-effective solutions for decreasing process risk. Many times, implementing a SIL solution will require increased equipment, which inevitably will require increased maintenance. Additionally, it is likely that the higher the SIL level, the more frequent the proof testing interval will be, which may ultimately increase the amount of system maintenance that is required. This is why the standards recommend a SIL based solution only when process risk cannot be reduced by other methods, as determined by LOPA.