Integration of the component of financial statement in highway maintenance planning

Highway agencies attempt to apply efficient accounting systems to help improve the transparency of their budget allocation and their overall performance. The accrual accounting system has been adopted to substitute the cash accounting system by many central governments around the world. The system reports transactions of economic value changes rather than when cash movements are made. The asset value and its depreciation determined by the accrual accounting system illustrate the total amount of economic value owned by an agency and the consumption of the future economic benefits for an asset. The age‐based depreciation approach, which is a traditional approach, is applied to determine the depreciation of an asset based on the defined useful life and the straight‐line depreciation method. The advantage of this approach is its simplicity and its ability to support the long‐term asset management system. The condition‐based depreciation is recommended as an alternative approach since the actual condition of an asset can reflect its depreciation. The depreciation of an asset based on the condition‐based approach is suitable for single‐year maintenance planning since the executives cannot estimate the required budget for replacing or preserving of an asset in the long‐term period. This research focuses on developing the new depreciation approach by integrating the age‐based and the condition‐based depreciation approaches in order to strategically plan long‐term highway maintenance and to enable the actual condition of an asset to be reflected.     

Directed monitoring using Cuscore charts for seasonal time series

The most commonly used statistical process control charts to detect special causes are Shewhart and Cusum charts. However, the Cuscore chart is a contemporary alternative that is especially well suited for detecting special causes that can be modeled in advance based on their characteristic effect on the system. In this paper, we develop the appropriate Cuscore statistic and the required control limits to detect a mean shift in a seasonal time series process. The work is motivated by an application involving blood platelet orders placed with the Red Cross. We also compare the performance of the Cuscore chart to the Cusum chart in this application and find that the performance of the Cuscore, in terms of time to signal the special cause, is better than the Cusum chart. We find that this result holds even when faced with the mismatch problem, which pertains to the compatibility between the actual and expected information that the Cuscore statistic is predicated on. Copyright © 2006 John Wiley & Sons, Ltd.     

A Decision Support System for Flexible Pavement Treatment Selection

The current decision–making process of the Thailand Department of Highways (DOH) for pavement treatment selection is based on the engineering judgment of DOH practitioners, which causes inconsistency and ineffectiveness in treatment selections. In order to address these problems, Thailand Pavement Maintenance Decision Support System (TPMDSS) is developed in this study to help provide an effective guideline for flexible pavement treatment selection. TPMDSS integrates both the database management systems (DBMS) and the treatment decision model. A treatment decision model employs the causebased strategy, which follows a logical progression by synthesizing relevant pavement–related data to help identify pavement problems and recommend feasible treatments. The main components of TPMDSS are: (1) TPMS inventory module, (2) field inspection module, (3) pavement section analysis module, (4) distress explanation facility, and (5) reporting module. The developed system is verified and validated against the experts' judgment and actual test cases.