An interrupt’s type determines how time to failure is evaluated and how elapsed time is tracked within the simulation. Each type defines how values drawn from the uptime distribution are compared against the model’s internal clock, shaping when an interrupt is triggered.
The available interrupt types are:
- Wall Clock Interrupts are triggered based on elapsed simulated wall time. In this mode, the sampled value is treated as time between failures, meaning downtime is included in the timing. Wall Clock interrupts are best suited for scheduled events that occur at fixed intervals, such as lunch breaks, shift changes, or safety meetings.
- Uptime – Competing Interrupts are triggered based on accumulated uptime, defined as the time a node is actively processing material (for example, when Actual Rate > 0). In competing mode, uptime continues to accumulate across multiple potential interrupts, with the first event to reach its threshold occurring. This mode is best used for random failures or stochastic interruptions, where multiple failure mechanisms may compete to stop operation.
- Uptime – Cumulative Interrupts are also driven by accumulated uptime, but in cumulative mode, progress toward failure is preserved across cycles. This makes it well suited for wear-based or consumption-driven behavior, such as tool degradation, roll changes on packaging lines, or recharge and refill scenarios.
In addition to uptime-based interrupts, ReliaSim supports volume-based interrupts, which can also operate in either competing or cumulative modes. These allow interruptions to be triggered based on material throughput rather than elapsed time—useful for modeling events driven by processed volume, such as filter replacement, material changeovers, or wear proportional to production. Also available are wear-based interrupts in both competing and cumulative modes. This is useful for modelling based on events driven by wear and tear on the process.
Together, these interrupt types allow you to model both time-driven and usage-driven behavior, supporting realistic representations of random failures, scheduled events, gradual wear, and volume-dependent maintenance within a single framework.