Root cause MORT

MORT excels in terms of organizational root cause identification, as factors such as functional responsibilities, management systems and policies are well covered, but this strength of the method requires an accurate description of the incident process, and an experienced MORT analyst who is knowledgeable and well-practiced in the methodology. 

The last requirement, i.e. if all (root)cause areas are included, was used to retrieve three pro-active methods indicating safety risks. All three methods address the entire socio-technical system (technical, human and organizational). These three methods are used to construct a new pro-active method of indicating safety risks, which includes the benefits and addresses the limitations of these three existing methods. The three methods evaluated are MORT, Johnson (Johnson, 1980), TRIPOD, Hudson (Hudson et al., 1991), and PRISMA, van der Schaaf (Schaaf van der, 1992). 

Varieties of public and proprietary predefined trees are available for use, although most owe some allegiance to MORT. The comprehensiveness of the different trees varies from some that may not fully reach root causes, to others that are very detailed with numerous categories and sub-categories. Several of these trees are listed in the appendix and examples of TapRooT SOURCE /Root Cause Map and Comprehensive List of Causes (CLC) < 4) are included on the CD-ROM. 

Yet, the MORT approach is extremely valuable in ensuring that the root causes of all accidents are identified and that corrective actions are taken. 

The Regulatory Body also has certified investigators, who use the Management Oversight and Risk Tree (MORT) to review some of the root cause analysis performed by the utilities and, in specific cases, carry out fully independent root cause analyses of the same events. 

MORT User s Manual. DE-76-45/4. SSDC-4. Systems Safety Development Center. EG G. Idaho. INPO Good Practice OE-907. Root cause analysis. 

The MORT system uses the term root cause in the sense of the most basic cause of an accident or incident (Cornelison, 1989). It can be traced back to a lack of adequate management control that results in substandard practices and conditions and subsequently in an accident. 

The theoretical basis of the different causal models becomes more obvious at the upper management level. MORT was the first comprehensive model to include organisational and individual factors at the top management level. At this level, it draws from quality assurance management principles. The SMORT and ILCI models have been influenced by this pioneering work and represent variations on the same theme. The concept of root causes originates from the MORT model. The checklist above shows the different items of a root-cause analysis. 

Cornelison, J.D., 1989. MORT based root cause analysis. Systems Safety Development Center, EG G Idaho, Inc., Working paper No. 27, Idaho Falls, Idaho. 

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