What Are 'active Errors' and 'latent Errors'

It has been clarified that human is the first cause for operational risk. The technology is growing up that make higher reliable equipment, but at the same time, some scientists believe that, it decreases the human reliability in operation. There are two factors that support this idea:

First factor is that in the past, machines and operating systems used to be operated directly by human. By developing technology and machines, human hands-on activity have less effect on machine performance and less physical task is needed to be done by operators with this technology development. The system automatically defense against the failures made by designers and the operator just observe the process through digital systems.

The second factor is related to human biological clock. Human have a very small cell cluster in the body which located in the way of optic nerves to brain. It calls Superachiasmatic Nocleaus (SCN). In case of sickness or disease, if these cells destroy, then the normal behavior and consciousness will be changed. The effect of this change is strong in human sleep and consciousness which has direct impact in human error.

When an accident happens and the root cause of that accident attributes to human error, the easiest way is to put all responsibility to human error. It is a fact that lack of sleep and fatigue is one of the major factors in human error, but human error is just a visible part of an accident. People are essentially human system components who controls by managerial, design and biological systems. Human contribution to risk is obvious but for minimizing that the system must consider the other root causes in design and operation of the system.

Type of errors is the main parameter in the discussion of human contribution to risk. There are two type of risk: Active and Latent.

- Active error: Type of error that is seeable and detectable immediately. Mostly some group of people like control operators are associated in this type of error. They receive the feedback information of the error in their operating system and they have overview of the error immediately. Example for active error is failure in operating heavy equipment and mistake in doing radiological surveys.

- Latent error: It is a type of error that should be combine with different other factors. Technical personnel and designers are mostly contributed to this type of error. Latent errors are not instant errors. Two categories of latent errors can be identified: operational and organizational. Typical operational latent errors include maintenance errors, which may make critical systems unavailable or leave the system in an error state. Organizational latent errors include design errors, which give rise to intrinsically unsafe systems, and management or policy errors, which create conditions that induce active human errors. Latent errors are unnoticed