**1. Introduction**

Major Incidents and Disasters (MID) a ffect societies and their inhabitants and result in medical and nonmedical consequences due to the imbalance between the needs and available resources [1]. MID managemen<sup>t</sup> is a multiprofessional process of organizing and managing the available resources and responsibilities for dealing with all humanitarian aspects of MID, specifically in mitigation, preparedness, response, and recovery phases to lessen the impact of emergencies [2]. Some strategies for MID managemen<sup>t</sup> include establishing command and control, reliable and e fficient ways of communication, information, organization, warning systems, stockpiling of resources, and the development of response plans for the mobilization and managemen<sup>t</sup> of resources such as personnel, equipment, volunteers, and emergency facilities. The e fficiency of the organizational structure in the response is paramount for the outcome of the event [2,3].

The initial approach to proper managemen<sup>t</sup> of MID is to increase the managemen<sup>t</sup> system's capacity, i.e., Surge Capacity (SC). Three broad areas of healthcare demand SC in response to a MID [4]. Firstly, Public Health Surge Capacity (the ability of the public health system to increase capacity for patient care, epidemiological investigation, laboratory services, mass fatality management, etc.). Secondly, Healthcare Facility-Based Surge Capacity (augments the response within the healthcare facility structure, e.g., triage-tent on hospital grounds). Finally, Community-based Surge Capacity (the public e ffort to support and augmen<sup>t</sup> the healthcare system). The four essential elements of SC, i.e., Sta ff, Stu ff, Structure, and System (4S), should rapidly and e ffectively be surged in the a ffected areas. Sta ff refers to available/alternative personnel, Stu ff refers to available/alternative equipment, Structures refer to Alternate Care Facilities (ACF), and systems are procedures and guidelines that govern the emergency managemen<sup>t</sup> process [5,6].

The expansion of a MID necessitates a new surge capacity (secondary SC), which underlines the need for extra e fforts to obtain additional resources still available within the managemen<sup>t</sup> system [7–9]. Nevertheless, a further expansion of the incident demands new approaches, policies, and adjustable preparedness within the community to scale up and down resources in a fast, smooth, and productive way, i.e., "flexible surge capacity" (FSC) [10]. The concept of FSC is concordant with the new paradigm of proactivity in disaster managemen<sup>t</sup> and emphasizes on risk reduction rather than focusing on pure relief operations to reduce vulnerability and increase resilience within communities [11]. Therefore, risk assessment and focus on all four elements of SC is necessary for achieving an FSC. Although the disaster managemen<sup>t</sup> cycle should incorporate, recognize, and value the participation of a ffected communities [12], it is necessary that adequate infrastructure is in place to ensure access to emergency services [13]. In this perspective, the readiness of hospitals is essential and among necessary measures, sta ff pools and new sta ff categories are needed to replace the regular sta ffing structure, and to reduce the risk of lacking qualified sta ff, e.g., leadership.

Although many functions and measures are necessary for proper and successful MID management, the command and control (C2) function remains the most critical function [14,15]. C2 emphasizes the leaderships' characteristics to command, control, communicate, collaborate, and coordinate [2,6,14,15]. Such ability o ffers an excellent opportunity for the leaders to attain a mutual goal, assess the situation from di fferent perspectives, overview all necessary measures, successfully sort out all injuries, treat them adequately and distribute them equally to designated medical facilities. Most hospitals have an emergency managemen<sup>t</sup> committee, which consists of predesignated positions and sta ff. Such a group of professionals needs to be trained to act decisively and quickly during crises. Previous studies have, however, shown that these committees su ffer from the rarity of MID, and thus, neither have the experience nor are trained enough to act as needed [15,16]. There is a lack of experience and knowledge about the managemen<sup>t</sup> process and collaboration with other partners, particularly in hospital and prehospital arenas. One specialty with the ability and knowledge to connect hospitals and prehospital organizations is Emergency Medicine [17].

Thailand is a disaster-prone country with a westernized healthcare system. Emergency Medicine residency training in Thailand started in 2004, during which the first Tsunami hit its southern part and caused mass casualties and structural devastation. One of the outcomes of this deadly event was understanding the needs for organizational and structural changes, and proper knowledge in command and control within the disaster managemen<sup>t</sup> system. Since then, many educational initiatives

such as MIMMS (Major Incident Medical Management and Support), and MRMI (Medical Response to Major Incidents) have been established and yearly conducted to raise the theoretical and practical knowledge of all sta ff [18–21]. Thai Emergency Physicians (EP), work within and outside the hospitals and are the point of contact and the first line of medical assessment [19,20]. This role requires the right level of structural and organizational knowledge of MID managemen<sup>t</sup> and merits a more responsible and critical role in response to major emergencies. One way to obtain such knowledge is through tabletop simulations training [21].

The Three-Level Collaboration (3LC) training model is used to train small groups of commanders up to hundreds of participants in the managemen<sup>t</sup> of MID. The development of the 3LC model was based on hypothesizing that the collaborative elements in a mutual task help reduce the organizational barriers [21]. The method has been compared with traditional exercises in several studies [22–24]. In one of these, the 3LC method improved collaboration as well as learning. At the 3LC exercise, 94.3% of the personnel perceived the exercise to be focused on collaboration. The traditional exercises reported a corresponding figure of 75.6%. The majority of the participants answered that they learned something new during the exercises (78.5%, traditional 64.9%). They also felt that the exercises had an impact on real-life activities during daily work (80.4%, traditional 61.7%) [24]. Organizational capabilities and limitations are enlisted to promote interplay with no hierarchical authority, and to promote the ability to switch between di fferent collaboration strategies as demanded by the specific situation. Collaboration training o ffers a chance to not only exhibit stability (the quality that one develops through drill and practice), but also to practice transitions, overlaps, fearlessness, improvisation, creative thinking, and the ability to handle unexpected situations. Such education is beyond the repeated learning that comes from the drill in control and command structures and other mechanical structures.
