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Troubleshooting network analyses

Release 9.3
Last modified March 2, 2010
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In ArcGIS Network Analyst, you may encounter certain error messages or unexpected behaviors. Ensure that you have turned on Errors and Warnings in the Network Analyst Options dialog box to understand the solution operation. You can open the Network Analyst Options dialog box by clicking the Network Analyst menu on the Network Analyst toolbar, then clicking the Options command.

Setting up error and warning messages

You can refer to the general behavior section below to understand what kinds of errors are reported by ArcGIS Network Analyst and why they occur.
Additionally, the solver-specific behavior section below discusses how Network Analyst solvers behave in different scenarios—for example, what happens during route analysis when the origin is not located on the network.

General Behavior

There are five kinds of errors reported by Network Analyst, as discussed in the table below. The order in which these errors are discovered are as follows:

  1. Errors in definition
  2. Invalid locations
  3. Cardinality issues
  4. Reachability issues
  5. User aborted
Type of issue Description Example Output
Errors in definition The analysis problem is incorrectly defined.
  1. During route analysis, the attribute used as impedance is not found, as it is incorrectly named, for example, "Unable to find attribute Times."
  2. During route analysis, hierarchy settings are invalid; for example, "Invalid max value 2 for hierarchy level 2. Has to be greater than hierarchy value 3 for hierarchy level 1."
An error message is generated. No solution is found.
Invalid locations Some or all of the network locations are not located on the network. In such cases, two alternatives exist:
  • Invalid locations are ignored.
  • Invalid locations are not ignored.
  1. During route analysis, some of the stops are not located on the network.
  2. A stop is located on an edge that is restricted in both directions.
  3. A stop is located on a edge that is blocked at both ends with barriers.
  4. A located stop has incorrect time window attributes.
If invalid locations are ignored, a partial solution is found using the located network locations. Additionally, a warning message is generated about the unfound network locations that were ignored. If invalid locations are not ignored, no solution is found and an error message is generated.
Cardinality issues The number of valid locations is less than the minimum number of locations required for the analysis. During route analysis, there is only one valid network location. An error message is generated. No solution is found.
Reachability issues Some of the network locations cannot be reached.
  1. Part of the network is not connected to or is isolated from the remaining network.
  2. Hierarchy is disconnected or incorrect.
  3. During closest facility analysis, the closest facility lies beyond the cutoff cost.
Output depends on the solver and the analysis settings. In some cases, a partial solution with a warning message is found. In other cases, no solution is found, and an error message is generated.
User Abort The user aborts the analysis by pressing the Esc key. During route analysis, the user presses the Esc key after clicking the Solve button Solve and before the analysis is complete. An Abort message is generated.

Solver-specific behavior

The following rules apply to each solver:

Route solver

Route solver using the Reorder Stops To Find Optimal Route option

Closest facility solver

Service area solver

OD cost matrix solver

Vehicle routing problem solver

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