1. A computer-implemented method for improved hydrocarbon production forecasting, the method comprising: a. obtaining, at a computer processor, an initial integrated production model representative of at least two interconnected subsurface tanks, at least one well, and a surface network, wherein the surface network comprises multiple components including at least one pipeline; b. parameterizing, via the computer processor, a subsurface part of the integrated production model by using material balance to characterize the at least two interconnected subsurface tanks; c. parameterizing, via the computer processor, a well part of the integrated production model based in part on well geometry; d. parameterizing, via the computer processor, the surface network based on the multiple components of the surface network; e. combining, via the computer processor, the parameterized subsurface part, the parameterized well part and the parameterized surface network into a reduced-constraint integrated production model wherein the combining comprises removing redundant constraints from at least the parameterized subsurface part or the parameterized well part or the parameterized surface network; and f. forecasting, via the computer processor, hydrocarbon production based on the reduced-constraint integrated production model.