BACKGROUND: Resilience engineering (RE) is a new paradigm that can control incidents and reduce their consequences. Integrated RE includes four new factors—self-organization, teamwork, redundancy, and fault-tolerance—in addition to conventional RE factors. This study aimed to evaluate the impacts of these four factors on RE and determine the most efficient factor in an uncertain environment. METHODS: The required data were collected through a questionnaire in a petrochemical plant in June 2013. The questionnaire was completed by 115 respondents including 37 managers and 78 operators. Fuzzy data envelopment analysis was used in different α-cuts in order to calculate the impact of each factor. Analysis of variance was employed to compare the efficiency score means of the four above-mentioned factors. RESULTS: The results showed that as α approached 0 and the system became fuzzier (α = 0.3 and α = 0.1), teamwork played a significant role and had the highest impact on the resilient system. In contrast, as α approached 1 and the fuzzy system went toward a certain mode (α = 0.9 and α = 1), redundancy had a vital role in the selected resilient system. Therefore, redundancy and teamwork were the most efficient factors. CONCLUSION: The approach developed in this study could be used for identifying the most important factors in such environments. The results of this study may help managers to have better understanding of weak and strong points in such industries.
Analysis of Variance* ; Plants* ; Surveys and Questionnaires

OBJECTIVE: Our aim was to determine the correlation between dental treatment need as assessed by the components of the index of orthodontic treatment need (IOTN) and a self-evaluation questionnaire in a population selected from the dental clinics of Shiraz, Iran. METHODS: The dental treatment needs of 240 participants (120 men and 120 women) were measured on the basis of the IOTN dental health component (IOTN-DHC), IOTN aesthetic component (IOTN-AC), IOTN AC determined by the examiner (IOTN-ACE), and a self-evaluation questionnaire (SEQ). The correlations between the treatment needs assessed by all the methods as well as the correlations of the treatment needs with age and gender were assessed using a Spearman's correlation coefficient (alpha = 0.01). RESULTS: All methods were significantly correlated (p < or = 0.001). The associations of IOTN-ACE with IOTN-DHC and SEQ were moderately significant (rho = 0.49 and 0.41, respectively). The associations of IOTN-AC with IOTN-DHC and SEQ were weakly significant (rho = 0.24 and 0.35, respectively). The IOTN-DHC was moderately associated with SEQ (rho = 0.53). Gender and age were not associated with treatment needs estimated by any of the methods used (p > 0.06). CONCLUSIONS: The correlations between the self-evaluation and the IOTN components in young adults were close to those reported in children, and IOTN-ACE was more reliable than IOTN-AC.
Child ; Dental Clinics ; Diagnostic Self Evaluation ; Humans ; Index of Orthodontic Treatment Need ; Male ; Surveys and Questionnaires ; Young Adult