Introduction
Distribution of relief items is one of the special and important functions in response to natural disasters. Significant disruption in distribution operations can increase financial costs and human loss. Incorrect estimation of the demand, failure to correctly identify the affected people, security problems during the distribution of relief items, and non-optimal allocation of relief items to the affected people are among the deviations witnessed many times in past crises. This study aims to identify and assess the risks of failure in relief items distribution by the Iranian Red Crescent Society (IRCS). 

Methods
In this study, we used the failure modes and effects analysis (FMEA). One of the challenges of applying this technique is the design of risk assessment scaling matrices. The incomplete recording of information related to the occurrence and severity of the failures of rescue operations in past crises in Iran makes it difficult to assess the risks based on a scale of 1 to 10. In this research, the risk assessment scales were revised after holding various meetings with the project team and according to the literature review (Mangla et al., 2018; Zhu et al., 2021) and considering the limitations of information recording in the IRCS. In addition to identifying and assessing risks, various interviews were conducted with the rescue and relief experts of the IRCS regarding the issues and problems of the distribution of relief items. A list of the most important issues and challenges in distributing relief items was thus prepared.

Results
The distribution operation was divided into three main processes of crisis assessment (including 3 sub-processes and 12 activities), accident analysis and decision-making by the command system (including 3 sub-processes and 20 activities), and relief item distribution (including 6 sub-processes and 20 activities). The total number of identified risks in three main processes was 104. The risks were categorized into nine groups: Communication management, human resource management, information management, logistics management, operation management, time management, budgeting, security issues and out-of-control risks. Information management with a frequency of 27 risks contributed to 26% of the total risks. By performing Pareto analysis, 4 risk groups (out of 9 groups) including information management, operation management, logistics management and time management contributed to 83% of the risks in total and were considered as the most important risk groups. 
After implementing the risk assessment phase, 20% of the identified risks (n=21) were considered unacceptable. The consequences of about 80% of the risks were time delay, disruption in the distribution process, and reworking of activities. In total, out of 104 identified risks, 52 risks did not have a control mechanism and 52 risks had a current control mechanism to reduce and eliminate risks. Out of 21 unacceptable risks, 10 risks had current controls; the effectiveness of these current controls needs to be evaluated and modified due to the unacceptability of these risks

Conclusion
In general, due to the high level of identified risks, it can be concluded that the current control mechanisms in the IRCS are not effective and need serious revision. Designing and implementing technological solutions such as designing information systems for managing distribution operations, preparing documents required for distribution operations, using new technologies such as rescue drones and tracking systems and assigning separate teams to distribute relief items are the most important recommendations proposed to control and reduce identified risks. The largest share of the proposed solutions was related to designing information systems for different areas of distribution operations with 25 iterations, which highlights the importance of mechanizing processes related to distribution operations and using new technologies. 
The most important challenges in the process of distributing relief items were the lack of transparency in the distribution process; the weakness of information systems in identifying or tracking the affected people and distributing relief items; weakness in accident assessment, accommodation, storage, and transportation of goods; the overlapping work of organizations; lack of information regarding the implementation of the distribution process; and complexity and high uncertainty. 

Ethical Considerations

Compliance with ethical guidelines
In this study, all ethical principles were considered. Since no experiments were conducted on animal or human samples, no ethical code was obtained.

Funding
This article was extracted from a research proposal funded by the Deputy for Education, Research and Technology of the Red Crescent Society of the Islamic Republic of Iran.

Authors' contributions
Methodology, writing initial draft, editing & review, visualization, supervision, and project administration: Ehsan Saghehei; Conceptualization, validation, analysis, investigation, resources, and funding acquisition: All authors.

Conflicts of interest
The authors declared no conflict of interest.

Acknowledgments
The authors would like to thank the Deputy for Education, Research and Technology of the Red Crescent Society of the Islamic Republic of Iran for the support, and people from the Red Crescent Society of Hamadan Province, including Mr. Ali Sanjarbeigi (CEO), Mr. Fazlollah Kalhori (Deputy Chief of the Rescue and Relief Organization), Mr. Mojtaba Hayati (Head of Support Department), Mr. Asghar Mazaheri (Head of Operations Department), and Mr. Mohammad Mosivand (Head of Intercity Rescue and Relief Base) for their assistance in this study.