When a model starts, the equations are assembled into the main differential equation system. During the simulation, this DES is solved by one of the numerical methods built in AnyLogic. AnyLogic provides a set of numerical methods for solving ordinal differential equations (ODE), algebraic-differential equations (DAE), or algebraic equations (NAE).
You can change numerical methods used for solving equations in the Numerical methods section of the model's Properties view.
Differential equations – method used to solve ordinary differential equations (Euler and RK 4 are available).
Algebraic equations – method used to solve algebraic equations (Modified Newton, Fast Newton, Classical Newton).
Mixed equations – method used to solve algebraic-differential equations (RK45+Newton, Euler+Newton).There you can also configure numerical methods used for solving equations: