SENTINEL has three dimensions: hazard & exposure, vulnerability and lack of coping capacity.

Each dimension encompasses different categories. Categories cannot be fully captured by any individual indicator, but serve to meet the needs of humanitarian and resilience actors. We can say that the selection of categories is user-driven (for example, UNISDR may follow the institutional category index in the coping capacity dimension while UNICEF and WFP may be more interested in the category of vulnerable groups in the vulnerability dimension). Underlying factors that contribute to the ranking results can be sought down through the levels depending on how narrowly the users intend to target their interventions. Each category can be broken down into components that capture the topic and are presented with a carefully chosen set of indicators.
The model of SENTINEL can be split into different levels to provide a quick overview of the issues in need of targeted actions:

• Ranking level
• Concept level - dimensions
• Functional level - categories
• Component level - sets of indicators that capture the concept of each category

The hazard & exposure dimension reflects the probability of physical exposure associated with specific hazards. There is no risk if there is no physical exposure, no matter how severe the hazard event is. Therefore, the hazard and exposure dimensions are merged into hazard & exposure dimension. As such it represents the load that the community has to deal with when exposed to a hazard event. The dimension comprises two categories: natural hazards and human-induced hazards, aggregated with the geometric mean, where both indexes carry equal weight within the dimension.

The main focus of humanitarian organizations is people, which is the element at risk contemplated in the SENTINEL composite index. The impact of disasters on people in terms of number of people killed, injured, and made homeless is predominantly felt in developing countries while the economic costs of disasters are concentrated in the industrialized world. The Vulnerability dimension addresses the intrinsic predispositions of an exposed population to be affected, or to be susceptible to the damaging effects of a hazard, even though the assessment is made through hazard independent indicators. So, the vulnerability dimension represents economic, political and social characteristics of the community that can be destabilized in case of a hazard event. Physical vulnerability, which is a hazard dependent characteristic, is dealt with separately in the hazard & exposure dimension.

There are two categories aggregated through the geometric average, socio-economic vulnerability and vulnerable groups. The indicators used in each category are different in time variability and the social groups considered in each category are the target of different humanitarian organizations. If the first category refers more to the demography of a country in general, the vulnerable group category captures social groups with limited access to social and health care systems.

For the coping capacity dimension, the question is which issues the government has addressed to increase the resilience of the society and how successful their implementation is. The coping capacity dimension measures the ability of a country to cope with disasters in terms of formal, organized activities and the effort of the country's government as well as the existing infrastructure which contribute to the reduction of disaster risk. It is aggregated by a geometric mean of two categories: institutional and infrastructure. The difference between the categories is in the stages of the disaster management cycle that they are focusing on. If the institutional category covers the existence of DRR programmes which address mostly mitigation and preparedness/early warning phase, then the infrastructure category measures the capacity for emergency response and recovery.