Known issues and limitations

The following features are not yet supported in the new simulator. Simulating a schedule with these features will lead to an error or to unexpected results.

• Base + Delta units. You cannot assign these units to the new simulator in the Topology page.

• Blenders. You cannot assign blenders to the new simulator in the Topology page.

• Exports. This causes a validation error.

• Recycles in the topology. This causes a validation error.

• Loops involving distillation units. This causes a validation error.

• Constraints on non-modeled properties. The simulation stops with an error if such a constraint is encountered.

• Overrides, except for the initial baseline state. All other overrides during the schedule are ignored.

• Rules. The simulation continues but rules are ignored.

• Rate targets. The simulation continues but targets are ignored.

• Conditional activities. These are treated as manual activities, and the associated conditions are ignored.

The following is a list of known issues affecting the new simulator, or instances in which the new simulator behaves differently from the current simulator.

Connections from classic to new simulator assets

All assets assigned to the new simulator must be strictly upstream of all assets assigned to the classic simulator.

This includes implied connections. For example, if asset A has a rate target that uses a calculation depending on asset B, then you cannot assign A to the new simulator and B to the classic simulator. Any other assignment is allowed.

Note that, in the above example, the rate target would not work with the new simulator in any configuration, since the new simulator does not support rate targets. The point of the example is to show an implied connection that would cause a conflict between the two simulators over which assets they control.

Other possible implied connections include rules (with calculations), overrides (with calculations), conditional activities and certain types of manifold connections.

Running gauge tanks

• Property and composition alerts are not issued for running gauge tanks.

• Running gauge tanks only conserve one between weight or volume, according to whether the flow rate unit of measure for the tank is weight- or volume-based.

• Activities downstream of a running gauge tank are split according to the Gauge Frequency Calculation value in the Simulation Settings dialog. For example, if the value is four hours the flow downstream of the tank will be modeled as a series of four-hour activities. This happens whenever the tank is filling at the same time.

Manifolds

• Manifold configurations are supported only when using ratios to define outgoing flows. Absolute rates are ignored.

• Sequential flow to manifold destinations is not supported.

Blends

• If a blend crosses the simulation end time, the transferred amount is calculated only until the simulation end time, rather than until the blend end time. This affects the flow rate, which is calculated using the whole blend period.

• Blend simulations, either manual or automatic, do not show an error message if the simulation cannot be completed. In these cases the simulation stops without user feedback.

Alerts

Alerts for constraint violations are sometimes issued even if the affected value exactly meets a constraint limit, without surpassing it.

Activities

When two activities with the same origin and destination overlap, the second activity is not taken into account during the overlap period. As a result, the total amount of transferred material is lower.

Pipelines

Some batch routings for pipelines are not supported. For example, initial outflow destinations are not supported, and manual activities can sometimes flow to a different destination than in the current simulator.

Overrides

Overrides are not populated with simulated data.

Progress bar

During simulation, the progress bar at the bottom left corner of the scheduling environment does not display progress for the new simulator, but only for the classic simulator.