Communication failures

The traditional approach, because it sees the major causes of errors and accidents as being attributable to individual factors, does not encourage a consideration of the underlying causes or mechanisms of error. Thus, accident data-collection systems focus on the characteristics of the individual who has the accident rather than other potential contributory system causes such as inadequate procedures, inadequate task design, and communication failures. 

The worker may have misheard instructions issued by the supervisor and thought that valve B was the required valve. Possible cause communications failure giving rise to a mistaken intention. 

Marx. J. "Cell Communication Failure Leads in Immune Disorder." Science. 896 iFebruaiy 12. 1993). 

An integral part of the system are the backup procedures. To deal with the problems of computer failure, loss of data base integrity or communication failures, a combination of approaches are used. The basic assumptions are One days worth of laboratory results on the lab computer are expendable in the sense that a significant fraction is still in the memory of the... 

System diagnostics Power failure Communications failure Environmental controls (EMI, RFI, etc.)... 

Misunderstanding Based on communication failures and inadequate information. 

The shootdown obviously involved a communication failure the F-15 pilots did not know the U.S. Army Black Hawks were in the area or that they were targeting friendly aircraft. Problems in communication between the three services (Air Force, Army, and Navy) are legendary. Procedures had been established to attempt to eliminate these problems in Operation Provide Comfort. 

Another common type of communication failure is in the problem-reporting channels. In a large number of accidents, the investigators find that the problems were identified in time to prevent the loss but that the required problem-reporting... 

For all SILs, it is recommended that the test coverage encompasses all application software SIFs and SIS failure responses (for example, power supply failures, processor failure, input hardware failure, output hardware failure and communication failures). However to further reduce any errors remaining in the software, for higher SILs it is recommended that the following additional testing is carried out ... 

Instrumentation equipment can fail in different ways. We call these "failure modes." Consider a two-wire pressure transmitter. This instrument is designed to provide a 4 - 20 milliamp signal in proportion to the pressure input. Detailed failure modes, effects, and diagnostic analyses of several of these devices reveal a number of failure modes frozen output, current to upper limit, current to lower limit, diagnostic failure, communications failure, and drifting/erratic output among perhaps others. These instrument failures can be classified into failure mode categories when the application is known. 

Teams, like individuals, may erode or create safety. For instance, in their study of communication in the operating theatre, Lorelei Lingard and colleagues (2004) classified about a quarter of operation relevant communications they observed as communication failures. Events were classified as failures because they were made too late or too early, because essential content was missing. 

Lingard, L., Espin, S., Whyte, S. et al. (2004) Communication failures in the operating room an observational classification of recurrent types and effects. Quality and Safety in Health Care, 13(5), 330-334. 

Communication failure Pressure transmitter fails (HIPPS) Logic solver fails (HIPPS)... 

A CANopen communication system has been applied. Here, measures have been implemented to detect communication failures. This includes bit errors, delayed messages, lost messages etc. lEC 62280 for communication in closed systems has been applied to diagnose possible faults with sufficient... 

Sutcliffe, K.M., Lewton, E. and Rosenthal, M.M. 2004. Communication failures An insidious contributor to medical mishaps. Academic Medicine, 79(2), 186-94. 

It is a real drama that originally aired on television in the late 1990s on the History Chaimel for a home audience. A lucky survivor tells of his remarkable escape and defines the sense of confusion on the scene. As the story unfolds, the viewer sees the event not as a result of a sudden unpredictable fire and explosion, but as the consequence of communications failures via permits, poor safety training, and flawed emergency procedures, which together created an environment in which the tragedy grew into the ultimate catastrophe. 

The growing usage of low cost COTS components comes at the cost of potentially increasing the vulnerabihty of SCADA systems to node and communication failures and cyber attacks. The crash of SCADA network nodes usually... 

A preliminary list of user s failure modes are omission of a known requirement (the user forgets), the user is not aware of a specific requirement, a requirement specified is incorrect (the user misunderstands his/her own needs), and the user specifies a requirement that conflicts with another requirement. Failure modes of the analyst are the analyst omits (forgets) a specific user requirement, the analyst misunderstands (cognitive error) a specific user requirement, the analyst mistransposes (typographical error) a user requirement, the analyst fails to notice a conflict between two users requirements (cognitive error). Communication failure is requirement is misheard. Each such failure is applicable to all types of requirements. 

The dangerous failure modes of the control system should be determined. This should include the analysis of I/O, power, and communications failure. 

Fault tolerant ethemet (FTE) is quite a good solution. This has been developed by Honeywell. The FTE connects a group of nodes typically associated with communication paths between them, so the network can tolerate all single faults and many multiple faults. FTE can rapidly detect faults and, in case of communication failure. 

Rapid response In conventional Ethernet, there are two separate networks with each node (server) connected to both networks. The switchover time, in case of communication failure, is 30 s. FTE employs a single network and does not require a server, so changeover time is less. 

Cooperative Service Level Evaluator. This fault-tolerant distributed vehicular system must ensure its safe operation. Each vehicle implements a cooperative service level evaluator that on every round decides what would be the lowest common ability to meet the operational conditions for the next round. Therefore, the decision and its dissemination must be done in bounded time. Due to communication failures, the cooperative service level evaluator must be able to cope with participants or communication failures. 

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