###### Abstract
To benefit from the advantages of SCLP and MCLP, in this study, the idea of hybridization of these two models in an integrated model is addressed. The hybrid model is a multi-period model consist of strategic and tactical planning decisions. Strategic planning decisions include the location of the capacitated facilities, and tactical planning decisions include module assignment and demand points allocation. Figure 1 shows a schematic illustration of strategic and tactical decisions that are taken in each time period. Strategic decisions reflect the long-term goals that are taken to retain the system more viable. Tactical decisions are made to meet mid time goals that contribute to strategic decisions. Tactical decisions can be taken to respond with a faster action compared to strategic decisions [14; 15]. It is supposed that the facilities are only the piece of land with basic infrastructures that would be located using SCLP that cover all demand points in each strategic period in response to the fluctuating demands and capacitated facilities. After determining the located sites as the facilities, in each tactical period, the limited number of each module kind would be assigned to the facilities using modular MCLP to maximize the covered demands. As mentioned above, one of the main features of the hierarchical or modular concept is that the decisions of assignment can be made only for one time period, and the decisions can change for the later periods. This feature allows having a different arrangement of modules in each facility and in each tactical period in terms of module type, number, and size. Using this integrated framework, trying to cover all demand points in the upcoming strategic periods, more facilities can also be located as extension decisions as a response to the rising demand. As an integrated model, the objective of the proposed model in this paper is to maximize the profit gained from the income of covering demand points and the cost of locating facilities. Similar to covering location problems, one of the main applications of the hybrid covering model is locating aid centers or evacuation sites in the humanitarian relief situation. The definition of the facility in this study is similar to the one that is used in real management systems, i.e., public facilities mainly with large yards, such as parks, schools, or parking lots [16] that can be utilized as an aid center in most of the disasters because of their low vulnerability. These kinds of facilities are usually equipped with essential needs such as water, electricity, etc. and are announced as shelter locations beforehand to the residents. Different kinds of modules can be considered, such as ambulances, trucks, helicopters, first aid units, food providing units, sleeping tents, shower rooms, etc. The importance of modularization of resources and services becomes apparent when, in most of the disasters, the whole area is exposed to be damaged, and if the facilities were located having full equipment, they might be out of order due to the disaster itself. Modularization can also have a high impact on budget management, as the modules can easily be dispatched to the other affected areas in the upcoming future. The other application of hybrid covering location problem is in locating hospitals, distribution centers, and integrated production planning and warehouse location problems [17]. The main contributions of this study are summarized as follows. * In this paper, we try to benefit from the coverage concept of SCLP to locate the facilities (with the aim of providing access to the facilities for all demand points) and MCLP to locate the service providing units (with the aim of maximizing the coverage of demand nodes by the modules respecting the limited number of modules) in an integrated model. * The integrated model is capable of improving the service quality and exploiting the limited number of modules in a better way compared to the non-integrated approach.