Discrete simulators (such as ProModel, Arena, ExtendSim, and Witness) generally rely on a transaction-flow approach to modeling systems. Models consist of entities (units of traffic), resources (elements that service entities), and control elements (elements that determine the states of the entities and resources). Discrete simulators are generally designed for simulating detailed processes such as call centers, factory operations, and shipping facilities.

GoldSim differs from most discrete simulators in the following manner:

• GoldSim can simulate both discrete and continuous processes simultaneously. This is a distinct advantage when the system includes continuous flows or dynamics.
• GoldSim was designed to build "top-down" models of complex systems that focus on "big picture" issues. As such, GoldSim is much better at simulating systems that have many diverse components that must be coupled together in a consistent manner in order to understand the behavior of the entire system (e.g., strategic business models, supply chains, portfolios of assets and/or projects, complex programs).
• GoldSim is much better at simulating complex systems whose behavior is difficult to predict and/or poorly understood such that they have a high degree of uncertainty. Such systems include both natural systems (such as hydrological systems and ecosystems) and man-made systems (such as markets, businesses, and complex programs or development projects).
• GoldSim is dimensionally aware and allows you to use any type of units without having to perform conversions or worry about unit errors.
• GoldSim was designed to accommodate the addition of specialized extension modules, such as the Financial Module (for simulating financial instruments and processes), the Contaminant Transport Module (for simulating the fate and transport of chemical and radioactive constituents in the environment) and the Reliability Module (for simulating the reliability of complex engineered systems).
• GoldSim is less effective at tracking detailed, carefully engineered systems whose interactions are precisely defined and controlled (such as assembly lines and call centers). If your system can best be described using a transaction-flow approach using only discrete events, a pure discrete event simulator would generally be a more appropriate tool than GoldSim.