Asset Register Database Verification
It is critical to establish the validity and the accuracy of the asset database since it forms the basis upon which the valuation will be completed.
Very often there will be more than one database. It is important to note that all these should be examined. For example, for a typical water utility there may be a distribution information system for collection mains and manholes, a billing system database containing customer information, and other discrete databases for the SCADA system. It is important to note that spares forming part of the normal operations and maintenance of assets for service delivery should also be included.
Many organizations have digitized their construction drawings making this information now accessible in electronic format. Depending on the extent of the transition, some organizations may still retain information in hard copy formats such as drawings or field notes.
In addition to the existing databases, maps and records, previous valuation reports and documents on capital contributions will be useful.
The basic asset attributes necessary for DORC valuation are the material types, sizes, quantities, year constructed/ refurbished, the expected life and the condition of the assets.
Other external attributes impacting on construction and asset performance are also important. These attributes include but not necessarily limited to the ground type, development density, failure histories, and operating environment.
The information may be available in the database but they may be inaccurate or incomplete. Adjustments to the records may be necessary to bring the valuation outcome to an acceptable level of accuracy.
Inaccuracies may arise due to data entry error. Also, default values are often adopted for missing information. The preliminary evaluation should involve discussions with the appropriate personnel on the defined process for data capture to the distribution system database as to consistency and accuracy.
For a typical distribution network, key components of the verification process include:
Verification of Distribution Information System Records for Location and Length
It is usually impossible to verify all records in a database. A pragmatic approach is to randomly select samples from each representative area and carry out field inspection against actual attributes.
Also it may not be practical to verify all asset groups. Usually those groups which make up the largest proportion of the total asset base, are selected, such as mains and manholes or major structures such as lift stations.
Alternatively, based on the total number of records, a statistical sample can be selected from the population of the asset records.
The information recorded for each sample selected in relation to location and asset attribute such as length, material types and sizes are tested for accuracy by comparing the recorded information to base land information on the agency’s plans.
Completeness Testing for Lineal Assets Records
In addition to assessing completeness of records within a database, separate procedures should be developed to determine the approximate quantity of assets that have not been recorded in the database due to time delay between constructing the assets and processing the information into the database.
These procedures include contacting each construction unit/depot and requesting that a schedule be completed detailing all new assets constructed for which the appropriate distribution information systems records have not been processed. This includes both new assets as well as renewed assets.
The new assets information is then compiled summarizing the amount of assets not recorded in the database. The renewed assets are specifically excluded as these simply replace existing assets; to include them would result in double counting. However other attributes such as change in sizes, age etc should be updated accordingly.
In addition to determining the processing lag, the completeness of the database records can also be assessed based on inquiry of various personnel from different departments ranging from personnel involved with the original uptake of asset information to regional field crews.
Assessment of Construction Date as Recorded in the Information System
Recorded construction date for the population of asset records in an information system should be analyzed electronically to determine frequency of date constructed by decade, year, and by month where necessary. These construction dates distribution can be graphed and reviewed to assess the reasonableness of the recorded date of construction based on frequency and spread over time compared with knowledge of the development of the industry over the last century.
Anomalies should be discussed with appropriate asset owner’s representatives. Based on these procedures, an assessment can be made as to the accuracy of the recorded date of construction.
Default dates are sometimes adopted where actual dates were not known. In regard to this type of default date, the assets can be analyzed with reference to the development of the network in blocks of 10 years. If the spread of dates laid over time appears to reasonably match the development of the utility industry based on length of mains laid in feet for each decade and in each year, this indicates that the “default” dates are sufficiently accurate to be used for the purpose of modeling the age of the mains.