Systems-Oriented Incident Investigation

The earliest logic trees were based on engineering fault tree analysis methods. Today, companies use a number of variations or combinations of logic trees and call them by different names, such as Why Tree,< 9) Causal Tree,(20,21) Cause and Effect Logic Diagram (CELD),<22) and Multiple-Cause, Systems-Oriented Incident Investigation (MCS011).<23,24) tools have more similarities than differences. 

Causal Trees were developed in an effort to use the principles of deductive logic found in Fault Tree but make it more user-friendly. Originally, private companies developed the Causal Tree Method (CTM) for safety, process safety, and environmental incident investigations applications. Rhone-Poulenc, for example, was an early user.<20.21) Multiple-Cause Systems Oriented Incident Investigation (MCSOfl) is another name for the CTM. At this time, most companies use simplified versions of fault trees for complex incident investigations. 

MCSOII Multiple-Cause, Systems-Oriented Incident Investigation... 

Rohm and Haas uses Multiple-Cause, Systems-Oriented Incident Investigation techniques (MCSOII), or mac-soy. It is a direct adaptation of the Fault Tree Analysis logic and the Deming Principles of Systems and Quality. [10] The method was developed to improve the overall quality of investigations, to increase the uniformity of investigation made by various teams, and improve the usefulness of the proposed corrective actions. The quality of the mac-soy or MCSOII investigation is improved because the method [10]... 

Three major themes have been emphasized in this chapter. The first is that an effective data collection system is one of the most powerful tools available to minimize human error. Second, data collection systems must adequately address underlying causes. Merely tabulating accidents in terms of their surface similarities, or using inadequate causal descriptions such as "process worker failed to follow procedures" is not sufficient to develop effective remedial strategies. Finally, a successful data collection and incident investigation system requires an enlightened, systems oriented view of human error to be held by management, and participation and commitment from the workforce. 

Dowell, A. M. Guidelines for Systems Oriented Multiple Cause Incident Investigations. Deer Park, TX Rohm and Haas Texas Inc. Risk Analysis Department, 1990. 

Abstract The intermonomer interaction effect on electromagnetically induced transparency (BIT) in dipole-coupled dimer models with different orientations and intermonomer distances is investigated. The absorption properties are evaluated using the imaginary part of the dynamic polarizability a calculated by the quantum master equation method. It is found that BIT can be observed even in the dimer systems with near-degenerate excited states originating in an intermonomer interaction by adjusting the incident field frequency. 

In addition to measuring solid samples by the methods just described, the orientation of dyes in suspension has been investigated using electric dichroism (199-205). Electric linear dichroism (ELD) measures the change in the absorption of incident light linearly polarized parallel and perpendicular to the applied electric field direction, as schematically shown in Figure 19. This technique has been applied extensively for dye-polyelectrolyte solutions. For cationic dye-clay systems, the roll and tilt angles of dyes at the surface of clays have been derived by detailed analysis of the ELD. It should be noted that electric dichroism can be performed only in solution of low ionic conductivity. IntCTcalation compounds... 

Anything can become an objective—from investigating incidents to developing a new employee orientation program. You must decide the activities that are more important for your management system to work, and the ones that will help you create an effective safety management system. The objectives you select must be consistent with your basic safety policy. Objectives should be part of the normal operations of your company, and not special projects added onto the normal workload [2]. They must be integrated into your business as we discussed. 

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