NETWORK.WEAKPOINTS OpenBI

Single points of failure: the nodes and links whose loss alone splits the network, with the nodes and pairs each one cuts off.

Group: Networks. OpenBI’s own: DAX has no function of this name.

Syntax

NETWORK.WEAKPOINTS ( <links>, <from>, <to> [, <weight>] )

Returns

Table. A row a weak point, the most harmful first. Its columns: Rank and Kind; Node for a node, or From and To for a link; Cut off, Pairs cut and Share cut; and Weight.

Remarks

• A weak point is a node or a link that, lost on its own, breaks its part of the network into pieces: a single point of failure. Kind says which; a node fills Node, a link fills From and To.
• Pairs cut counts the pairs of nodes that could reach each other before and no longer can (for a node, pairs of the other nodes); Share cut is that over every pair that could. Cut off counts the nodes left apart from the largest piece that remains.
• The rows come with the most pairs cut first, then the most cut off, a node before a link, then in the nodes' order. Weight is a link's weight, or for a node the weights of its links added up.
• The links are taken both ways: a link one way joins its two ends as a link both ways does. A network with no weak point returns no rows.
• Rows where an end is blank, or where both ends are the same node, add no link; the end that is there still counts as a node.
• Several rows between the same two nodes make one link, and their weights add up. Without a weight each row adds 1, so a pair that appears three times weighs 3.
• With a weight, a row whose weight is blank or 0 adds no link either.
• Nodes are compared the way OAX compares values: text without regard to case, and 1 and 1.0 are the same node. A node written two ways is shown with the spelling whose characters sort first by code (ALICE before Alice); a column of the model keeps one spelling of each text, the first it loaded.
• In a measure, the table is the rows the filters leave, so the network follows the slicers and the page: a visual measures the network of the rows in view.

Compared with DAX

An OpenBI function: DAX has none like it, so a measure or query that uses it works in OpenBI only, not in Power BI or Analysis Services.

Examples

Where one failure splits the supply chain

The road from Plant B to Depot S is the worst single failure: Depot S, Shop 3 and Shop 4 lose the rest, half of all the pairs that could reach each other. Losing Plant B cuts off the same three, and its roads carry 55 pallets a day between them.

EVALUATE
VAR Chain =
    DATATABLE (
        "From", STRING, "To", STRING, "Pallets", INTEGER,
        {
            { "Supplier", "Plant A", 40 }, { "Supplier", "Plant B", 25 }, { "Plant A", "Depot N", 30 },
            { "Plant B", "Depot N", 10 }, { "Plant B", "Depot S", 20 }, { "Depot N", "Shop 1", 12 },
            { "Depot N", "Shop 2", 9 }, { "Depot S", "Shop 3", 14 }, { "Shop 3", "Shop 4", 6 }
        }
    )
RETURN
    SELECTCOLUMNS (
        NETWORK.WEAKPOINTS ( Chain, [From], [To], [Pallets] ),
        "Kind", [Kind],
        "Node", [Node],
        "From", [From],
        "To", [To],
        "Pairs cut", [Pairs cut],
        "Share cut", [Share cut],
        "Weight", [Weight]
    )

Related functions

NETWORK.CUTS, NETWORK.NODES, NETWORK.LINKS, NETWORK.FLOW.

Open Graph, OpenBI's graph library, does the work: biconnected_components, bridges, connected_components, strength. See the OAX network functions and Open Graph.

Last updated 6 November 2026 · OpenBI Studio 0.3.78