Development of a business case for scheduling utility vegetation management on a preventive vs. corrective maintenance basis – Phase Two

2013 | John W. Goodfellow, BioCompliance Consulting, Inc.

As electric service reliability and utility vegetation maintenance practices and reliability performance come under increased fiscal scrutiny, the need for an objective means of determining appropriate levels of resource commitment has become acute. This report contains the findings of a two-part project that was envisioned by the Utility Arborists’ Association and funded by the TREE Fund’s Utility Arboriculture Research Fund. The intent of this study is to lay the foundation for an analytic approach to determine optimal vegetation management spend and cycle times. The approach that has been identified and proposed considers the relationships between costs (direct and indirect), performance (safety and reliability) and customer satisfaction from a utility vegetation manager’s perspective.

The first phase of this project included a comprehensive review of relevant literature, and development of an initial list of variables that might be used in completing a more detailed economic assessment of utility vegetation maintenance resource requirements. Of the dozens of articles examined, fifty-four were identified as relevant to the objective. A project specific abstract of each of these references is included as an appendix to this report. A suitable method known as probability bow-tie (PBT) analysis was identified and used to structure the development of the list of variables.

In the second phase of the project, findings from the literature review and initial list of potential variables were used to construct a risk-based analytical model based on PBT analysis that facilitates evaluation of the economic efficiency of vegetation maintenance practices. This model was then augmented with an additional time-dependent framework used to evaluate optimal vegetation maintenance cycle periods.

As stated, the intent of this initial project was to identify methods that could be used to conduct more rigorous quantitative investigations. To that end, a two-stage model validation effort is being proposed. The first step would to be develop a logical strawman using existing industry data sets. The resulting hybrid vegetation management program attributes would be used to conduct an initial test of the model. The final validation test would be to conduct a pilot(s) at a cooperating utility.

For more information on this project, contact the researcher via TREE Fund at treefund@treefund.org.