Study of the Role of Latent Variables in the Trip Gas Sweetening unit by using Human Factor Analysis and Based on Fuzzy Hierarchy Theory: Case Study in the Gas Refinery

سابقه و هدف: حوادث یکی از مهم‌ترین علل بروز خسارت در یک سازمان می‌باشند که به‌واسطه سلسله‌ای از خطاهای اغلب جزئی و کم‌اهمیت یک فرد و یا یک مجموعه رخ می‌دهند. بنابراين شناخت الگو و ريشه‌يابي علل بروز خطا يک رويکرد مهم در درک و بهبود مديريت ايمني در صنايع مي‌باشد. این مطالعه باهدف شناسایی خطاهای انسانی منجر به حوادث با استفاده از روش تجزیه‌وتحلیل فاکتورهای انسانی و سیستم طبقه بندی (HFACS)  و تئوری تحلیل سلسله مراتب فازی (FAHP) از پالایشگاه‌های گاز انجام شد. روش بررسی: پژوهش حاضر برای حادثه توقف تولید استحصال گاز در واحد شیرین‌سازی پالایشگاه گاز انجام شد. بدین منظور با تشکیل یک تیم از 6 نفر مهندسین ارشد پالایشگاه، ابتدا تحلیل علت‌های ریشه‌ای رویدادها با متد نمودار استخوان ماهی تهیه گردید. سپس با ادغام روش تجزیه‌وتحلیل فاکتورهای انسانی و سیستم طبقه بندی و تئوری تحلیل سلسله مراتب فازی احتمال رخداد هر یک از علت‌ها تجزیه‌وتحلیل گردید. نتایج: نتایج حاصل از تحلیل برگه‌های کار 128 فعالیت تعمیراتی نشان داد که در سطوح 4گانه روش تجزیه‌وتحلیل فاکتورهای انسانی و سیستم طبقه بندی ، بیشترین خطای رخداد در سطح اول استفاده از قطعه کیفیت پایین (6.8%=p) و عدم تحلیل صحیح بودجه موردنیاز تعمیرات (2.6%=p) است، سطح دوم زیرگروه نظارت ناکافی سرپرست تعمیرات (3.59%=p)، در سطح سوم زیرگروه فاکتورهای انسانی مرتبط با وظیفه (۳٫۲۵%=p) و در سطح ۴ زیرگروه خطای مبتنی بر دانش پیمانکار (۳٫۲%=p) و عدم دقت پیمانکار در تکمیل چک‌لیست (۲٫۳۱%=p) بیشترین احتمال تأثیر علت در رخداد رویداد توقف واحد و  استحصال گازترش را دارند. نتیجه‌گیری: نتایج مطالعه حاضر نشان داد علت‌های مختلفی از جمله فردی، وابسته به فعالیت (وظیفه) موقعیتی و سازمانی دارند که برای حذف و یا کاهش این خطاها نیازمند برنامه‌ریزی و مدیریت صحیح و دقیق می‌باشد. افزایش اثربخشی آموزش کارکنان و بهبود نظارت بر عملکرد کارکنان به ترتیب بیشترین نقش را در کاهش وقوع رویدادهای ناشی از خطای انسانی در عملیات‌های تعمیر و نگهداری پالایشگاه دارند.   How to cite this article: Askarian A, Mirza Ebrahim Tehrani M, Seyed Mohammad Taghi Sadatipour SM, jozi SA, Marandi A. Study of the Role of Latent Variables in the Trip Gas Sweetening unit by using Human Factor Analysis and Based on Fuzzy Hierarchy Theory: aCase Study in the Gas Refinery. J Saf Promot Inj Prev. 2020; 8(1):46-57.Background and Objectives: Incidents are one of the most important causes of damages in an organization often occurring due to a chain of minor and trivial errors. Therefore, recognizing the pattern and root causes of the errors are an important approach in understanding and improving safety management in the industry. This study aimed to identify human errors leading to incidents in a gas refinery using human factors analysis and classification system (HFACS). Methods and Materials: The present study for conducted for the event of stopping the production of gas extraction in the gas sweetening unit of the refinery. So, a team consisted of six senior refinery engineers, first the analysis of root causes of events with Fishbone Diagram was prepared. Then, by combining the HFACS method and FAHP theory, the probability of occurrence of each of the reasons was analyzed. Results: Analyzing the worksheets of 128 activities in four levels of HFACS showed, that the highest errors rate were the first level use of Use low-quality equipment (p=6.8%) and Failure to properly analyze budget for overhaul maintenance (p=6.2%), the 2nd level of the sub-group of inadequate supervision of the maintenance supervisor (p=3.59%), the 3rd subgroup of Task-related human factors (p=3.25%) and the 4th sub-category of (p=3.2%) and Inaccuracy of the contractor in completing the checklist Contractor knowledge-based error (p=2.31%) with the most probability impact in trip gas sweetening unit incident. Conclusions: The results show that errors have various causes, including individual, activity, situational, and organizational errors that require careful planning and management to eliminate or reduce these errors. Increasing the training effectiveness of operators and supervision improvement respectively are the most important measures in decreasing human error-induced incidents in refinery industry maintenance. How to cite this article: Askarian A, Mirza Ebrahim Tehrani M, Seyed Mohammad Taghi Sadatipour SM, jozi SA, Marandi A. Study of the Role of Latent Variables in the Trip Gas Sweetening unit by using Human Factor Analysis and Based on Fuzzy Hierarchy Theory: aCase Study in the Gas Refinery. J Saf Promot Inj Prev. 2020; 8(1):46-57

Assessment of the Human Factors Analysis and Classification System (HFACS): Intra-rater and Inter-rater Reliability

Human error has been identified as the primary contributing cause for up to 80% of the accidents in complex, high risk systems such as aviation, oil and gas, mining and healthcare. Many models have been proposed to analyze these incidents and identify their causes, focusing on the human factor. One such safety model is the Human Factors Analysis and Classification System (HFACS), a comprehensive accident investigation and analysis tool which focuses not only on the act of the individual preceding the accident but on other contributing factors in the system as well. Since its development, HFACS has received substantial research attention; however, the literature on its reliability is limited. This study adds to past research by investigating the overall intra-rater and inter-rater reliability of HFACS in addition to the intra-rater and inter-rater reliability for each tier and category. For this investigation, 125 coders with similar HFACS training coded 95 causal factors extracted from actual incident/accident reports from several sectors. The overall intra-rater reliability was evaluated using percent agreement, Krippendorff\u27s Alpha, and Cohen\u27s Kappa, while the inter-rater was analyzed using percent agreement, Krippendorff\u27s Alpha, and Fleiss\u27 Kappa. Because of analytical limitations, only percent agreement and Krippendorff\u27s Alpha were used for the intra-rater evaluation at the individual tier and category level and Fleiss\u27 Kappa and Krippendorff\u27s Alpha, for the corresponding inter-rater evaluation. The overall intra-rater and inter-rater results for the tier level and the individual HFACS tiers achieved acceptable reliability levels with respect to all agreement coefficients. Although the overall intra-rater and inter-rater reliability results at the category level were lower than the tier level, both types of reliabilities achieved acceptable levels with inter-rater reliability being lower than intra-rater. In addition, the intra-rater and inter-rater results for the individual HFACS categories varied from achieving low reliability levels to being acceptable. Both the inter-rater and intra-rater results found that the same 5 categories among the 19 - Skill Based Error, Decision Error, Inadequate Supervision, Planned Inappropriate Operations, and Supervisory Violation - were lower than the required minimum reliability threshold. While the overall findings suggest that HFACS is reasonably reliable, the fact that there were 5 categories with low reliability levels requires further research on ways and methods to improve its reliability. One such method could be to focus on training by designing and developing a standard HFACS training program that improves its reliability, which will have the potential to enhance both the confidence in using it as an accident analysis tool and the effectiveness of the safety plans and strategies based on it