# A Methodology for the Design of Application-Specific Cyber-Physical Social Sensing Co-Simulators
## 2 State of the Art
### Social, Physical and Network (Cyber) Simulation
These simulators also enable some kind of batch simulation [103] where you can run some hundreds of simulations with the same or different parameters to later analyze the results generated in a log. In order to create a different scenario and different agent models some programming is required to define the agent behavior and place the different elements in the environment. In this case, specific knowledge of the language and the behavior models are required in order to create the desired simulation despite you can create a behavior composed of several predefined behaviors  
Table 3 compares all the social simulators described above. Finally, **cyber world simulators** (known as IT simulators or networks simulators) include, probably, the widest catalogue of simulation solutions among all the CPSS subsystems. On the one hand, it may be found the traditional networks simulators, such as the NS3 [104]. These simulators must be configured using a generic programming environment, as they usually do not present a graphic interface. Sometimes, it is possible to show the result graphically using third-party tools. These simulators are developed professionally, so research works are not usually focused on them. There are several simulators nowadays both open-source such as NS3 or OMNet++ [105] and proprietary such as OPNET [106] or NETSIM [107]. On the other hand, new instruments for the most recent and popular concepts on IT sciences, such as the Internet-of-things (IoT), have appeared and could be used in CPSS simulations. These proposals are still been developed and many researchers are working on this topic. Some examples are the IoT simulator Cooja [108], SimpleIoTSimulator [109] or AutoSim [110]. These tools used to incorporate a graphic environment to create the scenarios. However, the customizing options are much fewer than in traditional networks simulators. Social IoT simulators are a special case among the IoT simulators [111]. In these instruments, some aspects of the social human behavior are included in the models in order to, for example, represent the human movements. All IT simulators are event driven, \"jumping\" from one event to the following event in the simulation process. During the simulation, the logs generated from the processing of each event are presented (or stored) at each simulation step. Table 4 compares all the IT simulators described above. Methodology for the Implementation of Application-Specific Cyber-Physical Social Sensing Co-Simulators  
This work proposes the first methodology for the design of CPSS co-simulators. The proposed methodology supports the work of software architects, which is the first approach to the co-simulator creation. At this stage, generic discussions about the complexity of simulations to be performed are proposed; general questions about requirements, the users' profile, and the development team must be answered; and the global lines of the future implementation are stablished. In later phases (at implementation time) more specific problems (which are not the focus of this work) should be addressed. In particular, crucial aspects about the data formats and time representation should be solved. In order to organize these activities, we propose a four-step methodology for designing a CPSS co-simulator being able of fulfilling the users' needs and requirements:  
1. Selection of the co-simulation paradigm
2. Particularization of the general simulation model and simulation lifecycle
3. Selection of the appropriate coordination mechanism
4. Design of the user interface and results presentation  
Several authors have reported the interest of research on co-simulation. The possibility of simulating individual components using different simulation tools simultaneously and collaboratively