Safety
Safety Instrumented Systems and SIL to IEC 61511
Understand how a safety instrumented system protects a plant when control fails, from SIL targets to proof testing.
Safety Instrumented Systems and SIL to IEC 61511 is a free, self-paced online course from EDWartens for engineering students, apprentices, technicians and working engineers in machine building and automation. It has 15 modules and takes about 15.7 hours, with written notes, a practice task per module, a practical project and a final assessment of 15 questions (pass mark 60%). Learning costs nothing and needs only a free account. The optional EDWartens Certificate of Completion, verifiable by code, is a one-off US$44.99 for you; it is not a vendor credential. Updated 1 November 2026.
- Free
- Advanced
- 15.7 hours
- Self-paced
- Certificate optional
- Lab practice in your browser
No card, no trial. The course is free for good. Certificate US$44.99, optional.
- Who it is for
- Engineering students, apprentices, technicians and working engineers in machine building and automation
- Jobs
- Roles that use this skill: safety systems engineer, functional safety engineer, machine safety specialist and commissioning engineer. No course guarantees a job.
- Tools
- None required. Hardware: none required. Access to a plant P&ID and a cause and effect chart makes the practice tasks real.
- Updated
After this course you can
By the end you will be able to:
- Write a safety instrumented function with a trip point and safe state
- Follow a LOPA to a SIL target and check it with a PFDavg calculation
- Choose a voting architecture such as 1oo2 or 2oo3
- Read a safety requirements specification and name what is missing
- Plan a validation test and a proof test
Who it is for, and what you need first
Who it is for
Engineering students, apprentices, technicians and working engineers in machine building and automation.
Level: Advanced. Advanced. Assumes PLC or DCS basics and some field instrumentation experience, so it is best taken after any of the free PLC or DCS courses. No coding and no software licence needed.
What you need
Software: None required..
Hardware: None required. Access to a plant P&ID and a cause and effect chart makes the practice tasks real..
How this course works
Watch the lessons
Short video lessons, one module at a time, at your own pace.
Read the notes
Open the Reading tab for the written notes and diagrams of the module.
Practise in the 3D labOptional
Try the module in the free 3D lab, in your browser.
Check yourself
Answer the questions to see what stuck before you move on.
Final assessment
Pass the final once you have been through the modules.
Certificate, if you want oneOptional
Optional, with a page anyone can use to verify it.
What you learn
15 modules in order, at your own pace. 15.7 hours of video lessons, with written notes and a practice task in each module.
- 1Why a plant needs a safety layer39m
- 2BPCS, SIS and the safety instrumented function35m
- 3Functional safety, IEC 61508, IEC 61511 and LOPA49m
- 4PFD and the reliability arithmetic behind SIL32m
- 5The SIS loop end to end1h 1m
- 6Trip philosophy, fail-safe design and overrides, with lab practice: 56m
- 7Redundancy, voting and safety architecture59m
- 8Common cause failure and how SIS equipment fails50m
Show the other 7 modules
- 9The safety requirements specification50m
- 10SIS design and the documents it produces27m
- 11The application program in the safety logic solver36m
- 12Validation, verification and the SIS work process, with lab practice: 1h 3m
- 13Proof testing instruments and valves, with lab practice: 59m
- 14Maintenance, repair deferral and engineering practice53m
- 15Final assessment
Practise in the 3D lab
Find a valve's fail position, stroke-test it, and run interlock tests on a finished skid, the field side of a safety function.
- Flow loop and control valveProcess lab, about 45 minOpen in the lab (opens in a new tab): Flow loop and control valve
- Site acceptance and fault findingProcess lab, about 70 minOpen in the lab (opens in a new tab): Site acceptance and fault finding
Optional. Skip it whenever you like: it never blocks your progress or your certificate.
Course project, about 18 hours
LPG sphere SIS to IEC 61511: LOPA, SRS with 2oo3 voting, PFDavg verification, proof test and FAT on paper
Design, verify and document the safety instrumented system for a 600 tonne LPG storage sphere. You deliver a LOPA register, an SRS, a cause and effect matrix with an I/O list, a SIL verification with the PFDavg arithmetic shown, a proof test procedure and record, a FAT record, and a bypass and deferral register. No software is needed. The sample pack shows what a functional safety engineer hands an LPG plant.
- 8documents in the pack
- 8steps to follow
- 6things to hand in
- 18 hof work, at your pace
- Risk registerHAZOP and LOPA Register: LPG Sphere V-101
- SRSSafety Requirements Specification: V-101 Sphere SIS
- Cause & effectCause and Effect Matrix: V-101 Sphere SIS
- I/O listLogic Solver I/O List: HIMatrix F60, SIS Cabinet SC-SIS-1
- Test reportSIL Verification Report: PFDavg and Architectural Constraints, V-101 SIS
- ProcedureProof-Test Procedure and Record: SIF-01 High-High Level and SIF-03 Isolation
The project is optional practice. The certificate needs only the modules and the final assessment.
After the course, your next step
Show what you can do, then keep going in the same field.
A certificate you can verify
Finish the modules and pass the final assessment (15 questions, pass mark 60%) and you can add a certificate with a public verification page. One-off, US$44.99 for you. It is not a vendor credential.
Want a free certificate? Do the matching Free internship: 4 weeks, nothing to buy, with a free certificate of completion.
Instrumentation and Process Control
Eight short weeks of measurement, calibration and control loops: notes, diagrams, a few videos and practice in the Panel Lab and LADX Mini. Finish weeks 1 to 4 and the final, then claim a free Internship Completion Certificate with your real dates and study hours, and a QR code anyone can scan to verify it. Training, not employment.
See the internshipMore free courses
Roles that use this skill
- Safety systems engineer
- Functional safety engineer
- Machine safety specialist
- Commissioning engineer
These are the kinds of roles where the skill is used. We make no promise of a job or an interview.
Plain notes
- Free: the whole course, the notes, the practice tasks, the final assessment and support from practising engineers.
- Paid, and optional: the course certificate, and the Engineer-verified internship (the Free internship costs nothing).
- No job promise: the course teaches a skill. It does not place you in a job.
- Lessons by: Instrumentation Tools. Independent creators; the lessons stream from their own channels. EDWartens wrote the study plan, notes, practice tasks and assessments.
Instrumentation Tools. If you are one of these creators and want a lesson removed or credited differently, write to info@edwartens.com.
Practise what you learn in the free 3D lab
Technical work is judged on what you can do: wiring, commissioning, finding a fault. Doing a task yourself teaches more than watching it a second time, and a lab lets you try it safely before you meet real equipment. It does not replace working on real hardware.
- Practise safely, so a mistake costs nothing.
- The lab checks your work like a site test, so you know when it is right.
- Free, in your browser, with nothing to install.
Why learn with EDWartens
What you get with this course, and what comes after it.
- Free from the first lesson to the final assessment.
- Practice in a free 3D lab in your browser, with nothing to install.
- Video lessons with written notes and a project.
- An optional certificate that anyone can verify online.
- Free internships to keep practising afterwards.
Common questions
Is the Safety Instrumented Systems and SIL to IEC 61511 course really free?
Yes. Every module, practice task and assessment. You create an account so your progress is saved and the assessments can be marked. The certificate is the only paid item, and only if you want it.
What certificate does the Safety Instrumented Systems and SIL to IEC 61511 course give?
An EDWartens Certificate of Completion, issued when you have finished every module and passed the final assessment at 60 percent, with a verification code anyone can check. It is not a vendor credential and is never described as one.
Is this the same as a TUV or exida functional safety engineer certification?
No, and it is not equivalent to one. Those are paid, examined certifications awarded by certification bodies and they have their own fees, syllabus and eligibility rules. This course is preparation: it teaches the subject those exams are built on, so you arrive knowing the material rather than meeting it for the first time in a classroom.
Who made the video lessons in the Safety Instrumented Systems and SIL to IEC 61511 course?
Instrumentation Tools, on their own YouTube channel, credited in the Credits block at the foot of this page. EDWartens did not make the videos and the creator is not affiliated with EDWartens. What EDWartens wrote is the study plan, the notes, the practice tasks and the assessments.
What should I know before starting?
PLC or DCS basics and some field instrumentation experience. You should be comfortable reading a loop drawing and know what a transmitter, a solenoid and a shutdown valve do. Any of the free PLC or DCS courses on this site is enough of a foundation.
Do I need any software, hardware or a licence?
No. There is nothing to install and nothing to buy. If you can get hold of a P&ID, a cause and effect chart and a few SIS work orders from a plant you know, the practice tasks become much more useful, but the course works without them.
Does the course cover HAZOP?
No. It starts where the hazard study leaves off. LOPA, SIL determination, the SIL target and everything downstream of it are covered in full, but facilitating a HAZOP is a separate skill and this course does not teach it.
Who is the Safety Instrumented Systems and SIL to IEC 61511 course for?
Instrumentation, control, DCS and maintenance engineers in refineries, petrochemicals, chemicals, fertiliser and gas processing, EPC design engineers working on ESD and fire and gas packages, and instrumentation graduates who want to move towards the safety systems group rather than stay on general loop maintenance.
Do I have to use the lab?
No. The lab is optional practice. You can skip it whenever you like, and it never blocks your progress, the final assessment or your certificate.
Is the lab free?
Yes. Every lab level for this course opens in your browser, free, with nothing to install.
What topics does the Safety Instrumented Systems and SIL to IEC 61511 course cover, module by module?
The Safety Instrumented Systems and SIL to IEC 61511 course has 15 modules. It opens with "Why a plant needs a safety layer", goes through "BPCS, SIS and the safety instrumented function", "Trip philosophy, fail-safe design and overrides", "SIS design and the documents it produces" and "Maintenance, repair deferral and engineering practice" and ends with "Final assessment". The full list with minutes is under "What you learn" on this page.
What can I do after the Safety Instrumented Systems and SIL to IEC 61511 course?
After the Safety Instrumented Systems and SIL to IEC 61511 course: Say in one paragraph why a safety instrumented system is kept independent of the basic process control system; Write a safety instrumented function with a trip point, a safe state and a response time a designer can build from; Follow a LOPA to a SIL target and check it with a PFDavg calculation and a proof test interval. These are the practical outcomes the course is written around, and the final assessment of 15 questions checks them.
What software and hardware do I need for the Safety Instrumented Systems and SIL to IEC 61511 course, and does it cost anything?
For the Safety Instrumented Systems and SIL to IEC 61511 course, software: None required. Hardware: none required. Access to a plant P&ID and a cause and effect chart makes the practice tasks real. The course itself is free.
Is the Safety Instrumented Systems and SIL to IEC 61511 course suitable for me, and what level is it?
Safety Instrumented Systems and SIL to IEC 61511 is rated advanced. Advanced. Assumes PLC or DCS basics and some field instrumentation experience, so it is best taken after any of the free PLC or DCS courses. No coding and no software licence needed. It is written for engineering students, apprentices, technicians and working engineers in machine building and automation, and takes about 15.7 hours at your own pace.
Which jobs use the skills from the Safety Instrumented Systems and SIL to IEC 61511 course?
Skills from the Safety Instrumented Systems and SIL to IEC 61511 course (for example: say in one paragraph why a safety instrumented system is kept independent of the basic process control system) are used in roles such as safety systems engineer, functional safety engineer, machine safety specialist and commissioning engineer, and in functional safety engineer work. The course gives you practical evidence of the skill; it does not promise a job, and employers decide on experience and interview.
Start free today
Safety Instrumented Systems and SIL to IEC 61511, at your own pace. Add the certificate only if you want one.