SIL Verification of identified SIF loops & Preparation of SRS for IOCL Barauni Refinery

The country’s second refinery, the Barauni Refinery, was commissioned in July 1964 ,  with a refining capacity of 1 million metric tonnes per annum (MMTPA) to process Assam (Naharkatiya) crude oil. In 2002, the refinery capacity was revamped to 6.0 MMTPA, with secondary processing facilities such as the Hydrogen Generation Unit (HGU-1), Residue Fluidized Catalytic Cracker Unit (RFCCU), and Sulphur Recovery Unit (SRU) as part of  technological advancements.

Indian Oil Corporation Limited has awarded iFluids Engineering to carry out SIL Verification for the identified SIF loops & Preparation of Safety Requirement Specification SRS for Barauni Refinery.

Scope of work

  • SIL Verification to be carried out for approximately 250 no. of SIF loops identified in the SIL assessment study of Barauni Refinery.
  • Recommendations for implementation to be suggested if any gaps are identified in relation to the existing system during SIL assessment study along with SIL verification report.
  • SIL Verification calculations to be done using the commercially  available, reputed, or proven Software
  • The  Safety  Requirement   Specification (SRS) to be  made  in  accordance  with EC  61508  I 6151 standards
  • SRS to be prepared for all the SIFs that are indicated  in the SIL assessment Report by IOCL

SIL Verification

SIL Verification study is the process of calculating the average probability of failure on demand (or the probability of failure per hour) and architectural constraints for a safety function design to see if it meets the required SIL.

Software Requirements Specification (SRS)

Software Requirements Specification (SRS) is a document that describes what the software will do and how it should perform.

Software used

The software to be used is exSILentia.

Completion of Project

Project to be completed within 6 months from the date of site Handover


  • Final SIL Verification report to be submitted along with  the hardware/software modifications applicable for each SIF.
  • Final report of SRS to be submitted after incorporation of all comments from IOCL.
  • SIL verification workshop to be done at Barauni Refinery
  • Final reports shall be submitted in Two soft copies & I hard copy (3 numbers).