The reply relies on a variety of components. These embrace: (i) are there interactions between the entity and the surroundings, (ii) does the mannequin have a time part, (iii) is the mannequin a cohort or particular person degree mannequin, (iv) is the mannequin steady or discrete states, and (v) is it Markovian or not. The Brennan taxonomy of mannequin constructions helps present an summary of which mannequin kind to select primarily based on these issues.

The desk above is from Breeze et al. (2023), however tailored from Brennan et al. 2006 and Briggs et al. 2016.
To supply some examples of what Breeze et al. (2023) phrases complicated programs fashions:
Computable Common Equilibrium (CGE) fashions have been used to mannequin decisions which have cross sector impacts that affect the indications of the nationwide economic system. Partial differential equation fashions can be utilized to explain the dynamics of infectious illness transmission. Each CGE and Partial differential equation fashions have key similarities to system dynamics and describe aggregated populations. In infectious illness modeling, the time period individual-based mannequin is commonly used for ABMs [agent-based models]. IBMs have lengthy been used to incorporate spatial and social inhabitants construction related to transmission and have been generally utilized in modeling COVID-19 and impacting coverage choices. IBMs permit straightforward inclusion of behavioral change to challenge its results on transmission dynamics