英语翻译It is important to give detailed calculations of the IS

英语翻译
It is important to give detailed calculations of the IS index for a series of examples covering a range of process industry stages:from research to producing a new product until decommissioning of a plant after its useful life is over.A quick way to obtain an approximate value of the index is needed since,for several relative comparisons,this may be enough.（其中IS是本质安全）