Safety engineering

It is strongly related to industrial engineering/systems engineering, and the subset system safety engineering.

Depending on the sub-specialties involved, industrial engineering may also overlap with, operations research, systems engineering, manufacturing engineering, production engineering, supply chain engineering, management science, management engineering, financial engineering, ergonomics or human factors engineering, safety engineering, or others, depending on the viewpoint or motives of the user.

Safety engineering assures that a life-critical system behaves as needed, even when components fail.

Risks of this sort are usually managed with the methods and tools of safety engineering.

The two most common fault modeling techniques are called failure mode and effects analysis and fault tree analysis.

This analysis method is mainly used in the fields of safety engineering and reliability engineering to understand how systems can fail, to identify the best ways to reduce risk or to determine (or get a feeling for) event rates of a safety accident or a particular system level (functional) failure.

The two most common fault modeling techniques are called failure mode and effects analysis and fault tree analysis.

FMEA is an inductive reasoning (forward logic) single point of failure analysis and is a core task in reliability engineering, safety engineering and quality engineering.

These techniques are just ways of finding problems and of making plans to cope with failures, as in probabilistic risk assessment.

Two common methods of answering this last question are event tree analysis and fault tree analysis – for explanations of these, see safety engineering.

It is strongly related to industrial engineering/systems engineering, and the subset system safety engineering.

Use of methods that allow early detection of possible failures, in safety engineering, are integrated into the design process.

It is strongly related to industrial engineering/systems engineering, and the subset system safety engineering.

Safety engineering describes some methods used in nuclear and other industries.

Safety engineering is an engineering discipline which assures that engineered systems provide acceptable levels of safety.

When combined with criticality analysis, FMEA is known as Failure Mode, Effects, and Criticality Analysis or FMECA, pronounced "fuh-MEE-kuh".

Another common example is that in an elevator the cable supporting the car keeps spring-loaded brakes open.

This brake is usually an external drum type and is actuated by spring force and held open electrically; a power failure will cause the brake to engage and prevent the elevator from falling (see inherent safety and safety engineering).

Usually a failure in safety-certified systems is acceptable if, on average, less than one life per 10 9 hours of continuous operation is lost to failure.{as per FAA document AC 25.1309-1A} Most Western nuclear reactors, medical equipment, and commercial aircraft are certified to this level.

Safety-critical systems are commonly required to permit no single event or component failure to result in a catastrophic failure mode.

The typical approach is to arrange the system so that ordinary single failures cause the mechanism to shut down in a safe way (for nuclear power plants, this is termed a passively safe design, although more than ordinary failures are covered).

One of the earliest complete studies using this technique on a commercial nuclear plant was the WASH-1400 study, also known as the Reactor Safety Study or the Rasmussen Report.

Failure Mode and Effects Analysis (FMEA) is a bottom-up, inductive analytical method which may be performed at either the functional or piece-part level.

For functional FMEA, failure modes are identified for each function in a system or equipment item, usually with the help of a functional block diagram.

The effects of the failure mode are described, and assigned a probability based on the failure rate and failure mode ratio of the function or component.

Fault tree analysis (FTA) is a top-down, deductive analytical method.

In FTA, initiating primary events such as component failures, human errors, and external events are traced through Boolean logic gates to an undesired top event such as an aircraft crash or nuclear reactor core melt.

Fault trees are a logical inverse of success trees, and may be obtained by applying de Morgan's theorem to success trees (which are directly related to reliability block diagrams).

Fault trees are a logical inverse of success trees, and may be obtained by applying de Morgan's theorem to success trees (which are directly related to reliability block diagrams).

Quantitative FTA is used to compute top event probability, and usually requires computer software such as CAFTA from the Electric Power Research Institute or SAPHIRE from the Idaho National Laboratory.

Quantitative FTA is used to compute top event probability, and usually requires computer software such as CAFTA from the Electric Power Research Institute or SAPHIRE from the Idaho National Laboratory.

Quantitative FTA is used to compute top event probability, and usually requires computer software such as CAFTA from the Electric Power Research Institute or SAPHIRE from the Idaho National Laboratory.

Some industries use both fault trees and event trees.