The last – and most important – addition to Figure 1, which is necessary in the context of computational models, is that of a conceptual model. The conceptual model is the intermediate model that is created before implementing a computer version (Augusiak et al. 2014). It summarizes aspects of the objective that are considered relevant and important to the final computational model. It is also a representation of the target, although it is much cruder than the calculation model. In practice, the people who develop the conceptual model are not necessarily the same as those who create the computational model: a research group could be composed of theorems and programmers, the former designing the conceptual model that will then be implemented by programmers. For our purposes, it is useful to put the conceptual model in our visualization, as it will help us later to take into account the verification and validation of the model in this image. Again, there is no representational relationship between the conceptual model and the accounting model. On the contrary, both are the objective and the computational model is a mathematical implementation of the conceptual model. Alternatively, we can imagine the conceptual model as a crude description of the computational model. Unfortunately, the practice of sequential modeling is not always applicable. The system under review must be challenged in such a way that a highly stylized model can be associated with this system, at least remotely. This cannot always be the case.
In addition, the relationship between increasingly complex models is problematic when one model simulates another. This issue was discussed further in depth at Axtell et al. (1996) under the theme “Aligning Simulation Models” and subsequent work. However, despite its potential difficulties, there are already a few examples where the practice of sequential modeling has been very successful, see z.B. Axtell et al. (1996), Bednar – Page (2007), Gintis (2007) or Henderson – Isaac (2017). Develop and maintain a VV-A model plan. Before you start the acquisition program, develop a detailed VV-A plan. Contrary to the specification of the model itself, this plan should provide guidelines for each phase of the VVA and illustrate the difference between the verification and validation phases. The plan should also assign model specification requirements to model elements, identify model elements, model that need to be verified, and define model validation requirements.