GAMs

General Algebraic Modeling System (GAMS) is a high-level modeling system for mathematical optimization. It provides a specialized language and integrated development environment for formulating, solving, and analyzing optimization problems in fields such as operations research, economics, and engineering.

At the core, GAMS uses an algebraic modeling language in which problems are expressed with sets, parameters, variables, equations, and models. Users declare index sets and data, define objective functions and constraints, and group related equations into a model. The language emphasizes readable, math-like notation and supports both continuous and discrete variables.

Solvers: GAMS translates the model into solver input and calls external solvers. It relies on an external solver ecosystem and supports a wide range of linear, nonlinear, mixed-integer, and stochastic solvers through a solver interface. Examples include CPLEX, GUROBI, XPRESS, MOSEK, IPOPT, Knitro, SNOPT, and BARON, among others.

Workflow: data assignment, model declaration, solving, results. Typical workflow: load data into sets and parameters, declare variables and equations, define model and objective, use the solve statement with min or max, then retrieve results via display or parameter assignments.

Availability and usage: GAMS is proprietary software developed by the GAMS Development Corporation. It is distributed under commercial licenses and is widely used in academia under institutional agreements. The GAMS Studio environment provides an integrated editor, debugger, and project management.

Applications span energy systems, transportation, manufacturing, finance, and research, where large-scale, complex optimization problems are common.