Instead, the report points to inadequacies on the part of city officials and the project's initial systems integrator.

For example, city officials had based the original budget on an independent estimate that did not factor in costs such as new hardware needed to run the system. In addition, city officials later added more functionality to the project plan.

Meanwhile, the project's contractor, Ariston Consulting and Technologies, "was not always able to identify standardized ways of incorporating these additional items," resulting in higher costs, according to the report.

Ariston also failed to finish project documents on time and had staffing difficulties, it adds.

Portland ultimately terminated its contract with Ariston in 2008 and inked a new deal with SAP's Public Services arm to finish the project, the report adds.