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What is the failure rate for SIL certification?
During the SIL certification process, a concept we often mention is the equipment failure rate, which is a core term in SIL certification. To say that a SIL certification is incomplete or comprehensive without determining the failure rate is to say it's not thorough. So, what exactly is the concept of failure rate?
Firstly, to understand failure rate, we must comprehend what is meant by "failure." According to GB/T 20438.4 and also the definition in IEC 61508, failure is "the termination of the ability of a functional unit to perform a required function, or the operation of the functional unit in a non-required manner." A more intuitive way to understand this is: normally, y=f(x), but after failure, it becomes y≠f(x), where f() represents the pre-set function, and y stands for our safety expectations. This also explains why "function" is the same word used for both function and function in English.
This statement might be too formal and not easily understood by the general public. So, speaking in more colloquial terms, let's liken it to a lighting system. If the lighting system doesn't illuminate or doesn't do so according to our set requirements, then it's malfunctioning.
So said, you might know that when a product doesn't function according to our specified requirements, we can say it's failed. Then, what's the probability of this failure? That's the failure rate.
After understanding what failure is, we can start to categorize the types of failure. In the concept of functional safety, failures can be divided into two main categories based on their cause of generation: systematic failure and random hardware failure. Among them, random hardware failure is quantifiable. The calculation process of PFDavg is based on a probabilistic analysis of random hardware failure.
In the SIL certification process, we analyze the theoretical product model and market sales data to determine the product's failure rate, which, when combined with other parts of the SIL certification, forms a comprehensive system ensuring reliable and safe execution of safety functions.

SIL 2 and SIL 3 certifications are two different levels. According to international certification standards, the SIL 3 level is higher than the SIL 2 level. Specifically, this is manifested as:
A SIL1-rated actuator should have a failure probability controlled to ≥10^-6 and <10^-5 during continuous operation per hour.
SIL2 is from ≥10^-7 to <10^-6. SIL3 is from ≥10^-8 to <10^-7.
Of course, the requirements for a SIL3 level are much higher than those for a SIL2.
Most products currently meet the requirements with SIL2 or SIL3 certification levels.

The significance of obtaining SIL certification for products
1. SIL Certification's Impact on Product Accumulation:
We guarantee the accuracy of the product's specific functions.
(2) Enhances product acceptance and recognition within the industry.
(3) Certified products offer enhanced safety, thereby boosting the product's competitiveness.
(4) Customers typically believe: Certified = Acknowledged = The.
2. The cumulative impact of SIL certification on enterprises:
(1) Enhance corporate safety experience and proficiency.
(3) The company's research and development process is more standardized and verifiable.
(4) Enhanced safety guarantees are in place during incidents.
(5) Throughout the certification process, ensure the company's R&D level remains at a high standard.
If a project, system, or product achieves SIL certification, its quality and safety are also recognized and acknowledged. This not only enhances the company's market competitiveness but also significantly boosts customers' confidence in the product. Therefore, it is necessary to undergo SIL certification for a product that has a significant impact on life and property safety.

SIL Certification Level Preliminary Assessment Submission Document List
Product User Manual
2. Product Safety Feature List
3. Product Safety Manual
4. Failure Mode and Effects Analysis (FMEDA) Excel File
5. Quality Management System Certificate (ISO 9001)
6. Product Photos (including front and side views of representative models)
7. Product Design Documents (drawings, material reports, calculations, etc.)
8. Additional Information
SIL certification is a third-party assessment, verification, and certification based on standards such as IEC 61508 (GB/T 20438), IEC 61511 (GB/T 21109), IEC 61513, IEC 13849-1, IEC 62061, and IEC 61800-5-2, evaluating and confirming the Safety Integrity Level (SIL) or Performance Level (PL) of safety equipment. Functional safety certification primarily involves document management (FSM) assessments for the development process of safety equipment, hardware reliability calculations and evaluations, software evaluations, environmental testing, and EMC electromagnetic compatibility testing. SIL certification is divided into four levels: SIL1, SIL2, SIL3, and SIL4, encompassing both product and system levels, with SIL4 having the highest requirements.