Читать книгу Root Cause Failure Analysis - Trinath Sahoo - Страница 75

Latent failures are normally present in the system well before an failure occur and are most likely bred by decision‐makers, regulators, and other people far removed in time and space from the event. These are the managerial influences and social pressures that make up the culture (“the way we do things around here”), influence the design of equipment or system, and define supervisory inadequacies. They tend to be hidden until triggered by an event. Latent failures may occur when several latent conditions combine in an unforeseen way. Efforts should be directed at discovering and solving these latent failures rather than by localizing efforts to minimize active failures by the technician. Also, there are organizational influences such as communications, actions, omissions, or policies of upper‐level management directly or indirectly affect supervisory practices, conditions, or actions of the operator(s) and result in system failure or human error.

A distinction between active failures and latent conditions rests on two differences. The first difference is the time taken to have an adverse impact. Active failures usually have immediate and relatively short‐lived effects. Latent conditions can lie dormant, doing no particular harm, until they interact with local circumstances to defeat the systems’ defenses. The second difference is the location within the organization of the human instigators. Active failures are committed by those at the human–system interface, the front‐line activities. Latent conditions, on the other hand, are spawned in the upper echelons of the organization and within related manufacturing, contracting, regulatory, and governmental agencies that are not directly interfacing with the system failures

The consequences of these latent conditions permeate throughout the organization to local workplaces – control rooms, work areas, maintenance facilities etc. – These local workplace factors include undue time pressure, inadequate tools and equipment, poor human–machine interfaces, insufficient training, under‐manning, poor supervisor–worker ratios, low pay, low morale, low status, macho culture, unworkable or ambiguous procedures, and poor communications.

Within the workplace, these local workplace factors can combine with natural human performance tendencies such as l limited attention, habit patterns, assumptions, co complacency, or mental shortcuts. These combinations produce unintentional errors a and intentional violation committed by individuals and teams at the “sharp end,” or the direct t human‐system interface (active error).

Latent failures are those aspects of an organization which influence human behavior and make active failures more likely. Factors include:

 Ineffective training;

 Inadequate supervision;

 Ineffective communications;

 Inadequate resources (e.g. people and equipment); and

 Uncertainties in roles and responsibilities;

 Poor SOPs.

 poor equipment design or workplace layout

 work pressure, long hours, or insufficient supervision

 distractions, lack of time, inadequate procedures, poor lighting, or extremes of temperature

Latent failures provide great, potential danger to active failures. Latent failures are usually hidden within an organization until they are triggered by an event likely to have serious consequences.