1. A method of modelling an engine on a vehicle, comprising: determining, by one or more processors, a first solver for modelling the engine; wherein the first solver comprises a first routine configured for determining one or more parameters of the engine; obtaining, by the one or more processors, a first set of inputs associated with the first solver, wherein the first set of inputs comprises one or more inputs obtained from the first solver and one or more previous engine states; modelling, by the one or more processors, the engine based at least in part on the first set of inputs to generate a first set of outputs, wherein the first set of outputs comprises one or more parameters of the engine and one or more engine states; and providing, by the one or more processors, the one or more parameters to the solver.