Safety instrumented systems (SISs) are becoming increasingly complex and the proportion of programmable electronic parts is growing. The IEC 61508 global standard was established to ensure the functional safety of SISs, but it was expressed in highly macroscopic terms. This study introduces an evaluation process for hardware safety integrity levels through failure modes, effects, and diagnostic...

Nowadays software control large majority of systems that humankind use. Systems that software is used widely, such as transportation, military, medicine and avionics must be safe during operation. Fail in these critical systems may cause catastrophic results (i.e. loss of human life, loss or severe damage to environment or equipment etc.). In order to avoid failure on safety critical systems or...

According to the IEC 61508 functional safety standard, it is required to estimate the achieved safety integrity of the system due to random hardware failures. For a safety function operating in a low demand mode, this measure is the average probability of a dangerous failure on demand (PFDavg). In the present paper, four techniques have been applied to various configurations of a case study: fa...

The international safety standard, IEC 61508, presents several challenges to its users who are often not familiar either with safety engineering and management or with introducing a new standard. This paper first explores the background to the difficulties that companies experience in using the standard. It then discusses the difficulties that the standard poses, in the context of how a company...

Management of chemical sites and facilities has an obligation to conduct the operations on the site in such a way as to ensure the safety of people and the environment. In many countries this obligation is a legal requirement. Within recent years a new standard IEC 61508 has been published. This standard and its derivative standards are providing clear guidelines for the use of electrical, elec...

The ITER Interlock Control System (ICS) requires the application of IEC 61508 standard for all mission-critical (known as investment protection) control functions. Such functions must detect events integrated physical processes and distribute them to actuators with hard real-time constraints on order milliseconds or even microseconds. Systems able achieve these timing requirements are often bes...

In this paper selected aspects of human factors are discussed that should be taken into account during the design of safety-related functions for a complex hazardous installation and its protections. The layer of protection analysis (LOPA) methodology is used for simplified risk analysis based on defined accident scenarios. To control the risk the safety instrumented functions (SIFs) are identi...

Intelligent systems, such as intelligent automotive systems or intelligent robots, require a rigorous reliability/safety while the systems are in operation. As system-on-chip (SoC) becomes more and more complicated, the SoC could encounter the reliability problem due to the increased likelihood of faults or radiation-induced soft errors especially when the chip fabrication enters the very deep ...