A ReliaSim model represents your process as a connected network of nodes that define how material enters, moves through, and exits the system. At its core, every model has a clear starting point and ending point—typically represented by an initial buffer that supplies material and a final buffer that collects output. Between these endpoints, nodes are used to describe the key steps, constraints, and transformations that shape flow. This structure allows ReliaSim to simulate how local behavior influences overall performance.
Each node represents a meaningful element of the real process. Buffers provide storage and allow material to accumulate, making them useful for modeling queues, inventory, and decoupling between steps. Constraints define rate limits and often represent machines or operations that control throughput. Conveyors and accumulating conveyors model transport and movement, while splits and merges describe branching and convergence in the flow. Conversions, assemblies, and batch nodes capture changes in material form or processing logic. Together, these nodes define both the physical layout and operational logic of the system.
The connections between nodes determine how material moves through the model. By arranging nodes in sequence and linking them appropriately, you establish the pathways that govern flow behavior. As you build, it’s often helpful to focus first on capturing the major process steps and constraints before refining details. A model does not need perfect data to be useful—clarity of structure is usually more important than precision early on.
Once the core structure is in place, node parameters such as rates, capacities, and initial volumes can be adjusted to reflect operating conditions. These settings shape how material accumulates, where bottlenecks form, and how throughput evolves over time. Because each node directly influences downstream behavior, even small changes to a single element can ripple through the entire network. ReliaSim makes these interactions visible, helping you understand not just individual components, but how the system performs as a whole.
The Subsections that follow will outline each individual node type, as well as give a brief summary of it's use and properties.
To make a model reflect real-world conditions, interrupts are needed. There will also be following subsections regarding the use and structure of interrupts.