SILcet – Tool for SIL verification
SILcet tool helps you in calculations and SIL verification tasks of the safety instrumented functions (SIF) of the project. The main features are the following:
- It calculates the average probabilities of failure on demand (PFDavg), both of each of the subsystems and of the complete SIF. Also calculation of PFH (high demand SIF).
- It calculates the Safety Integrated Level (SIL) of the SIF taking into account the three requirements of the IEC-61508/61511 Standards (systematic capability, failure probability and architectural constraints according to the Route 1H or 2H).
- It allows to select different architectures for each one of the subsystems of the SIF (PFDavg: 1oo1, 1oo2, 2oo2, 2oo3, 2oo4, 1oo2D, 1oo3, 1oo4, 1oo5, 3oo3, 4oo4, 5oo5, NooN, Nx1oo2, 3oo4, 3oo5, 4oo5, 1ooM, etc. ; PFH: 8 architectures), as well as calculate complex configurations combining several groups of architectures.
- It allows adding other terms that affect the value of PFD and MTTFS, such as when using bypasses.
- In addition to the subsystems SENSOR, LOGIC SOLVER and ACTUATOR, a fourth subsystem can be added to include in the calculation the systematic failures (for example due to human errors) or any other concept.
- The data entry for the calculation and SIL verification can be done in different ways, either manually (with the failure rates or with the previously calculated PFD) and by importing the failure rates from the elements databases of the user.
- SIL Calculator: Easy-to-use option to calculate the SIL and MTTFS with 19 architectures and 4 subsystems (sensor, logic solver, 2 x actuator).
- It allows generating two types of reports of up to 70 SIFs (Safety Instrumented Functions). With the same license is possible to use and save an unlimited number of Excel files, one per project or unit (70 SIFs per file).
- Option to include the logic diagram of the SIF architecture in the reports. Download Sample Report.
- It allows you to enter the costs of the components of the SIF to compare the cost of different solutions.
- It allows calculating the β factor for common cause failures according to one of the methodologies recommended in IEC-61508.
- It compares SIL calculations of different SIF designs. New feature to perform a rapid test of the SIF behavior when changing the main parameters (it generates 12 different designs by adjusting TI, Cpt and/or DU/DD).
- New option in SILcet 4.0.4 to calculate PFDavg when making online proof tests (e.g.: Partial Stroke Test every 30 days with process in operation, and Full Stroke Tests every 3 or 4 years during maintenance overhauls. Equations are based on ISA TR84.00.03.
- New option in SILcet 4.1: macro to generate up to 10 lists of the selected SIFs in order to compare different configurations, for example by introducing different correction factors of the main parameters (failure rates, Cpt, TI, LT, Beta, MTTRdd, MTTRs).
- The tool is in English and the reports can be configured in any language.
- We also provide the Training Course “Design of SIFs and SIL calculation“, which includes real examples both for the modernization of existing SIS and for the design of new projects. This course is also available online (also a version in spanish).
- Both the SILcet tool and the training course have been developed following the recommendations of Standard IEC-61508/IEC-61511 for low demand safety functions, common in the process industry (more information about the used equations).
- SILcet is an Excel workbook that uses formulas and macros in Visual Basic.
- The technical requirements for the use of SILcet are the following: Windows 7, 8, 10 and Excel 2010 SP2, 2013, 2016, 365.
In which cases should I use a tool like SILcet?
- For calculating the SIL and MTTFS in the early stages of any project (pre-FEED, FEED, etc.)
- In the early stages of EPC projects to avoid later changes in design.
- To verify the SIL of complex configurations.
- To compare different designs of the Safety Instrumented Function.
- To analyze the sensitivity of the SIF to changes in the TI, Cpt, DU / DD parameters
- To verify the safety level of any new or existing installation.
- For the training courses on Functional Safety.
We have a Partners Program for all countries to develop the use of SILcet. Contact us if you are interested to know more.