Balance model validation

The Model Validation step detects and informs you about the following model network problems:

• Balance points with large discrepancies consisting of only constant flows

• Balance points consisting of only input flows or consisting of only output flows which have measured values

Model Validation takes corrective action to allow reconciliation to run even when there is a model error.

The second case, in which a balance point lacks either an input or and output side, has a particularly large effect on the overall material balance.

Figure: Input-only Configuration Model (model error)

In the figure above, you see that the node shown in red has only an input flow, and that flow has a measured value. Flow3 is the name of the input flow in this case – its measured and reconciled values are shown beneath the name. Because there is no output flow for the red node, the reconciliation algorithm forces the reconciled value of the input flow to zero. In the real plant, there was truly flow to the red node, and there should be an output flow from the node. Thus, the flow that in reality went through the node shown in red gets distributed by reconciliation to the other flows that serve as outputs from the process. The reconciliation corrects the other measurements by a large amount even though they are, in reality, good measurements.

The following figure is theoretical, because AVEVA Production Accounting actually detects this problem and takes corrective action to prevent the unbalanced, misconfigured node from corrupting the reconciliation for the other streams.

Figure: AVEVA Production Accounting avoids balancing misconfigured nodes that have only input or only output

AVEVA Production Accounting knows not to try to balance the misconfigured node, so it avoids forcing the reconciled value to 0.