An AHP-weighted aggregated data quality indicator (AWADQI) approach for estimating embodied energy of building materials

Purpose

Aggregated data quality indicator (ADQI) method has been used to estimate probability distributions of the input data in a life cycle assessment (LCA) to compensate for insufficient data in a statistical analysis. In a traditional ADQI, a multicriteria evaluation process, the impacts of various quality indicators under investigation are often equally weighted or unweighted despite the fact that some of them may weight more than the others on contributing to the overall data uncertainty. An unweighted ADQI (UWADQI) approach, though simple, may lead to incorrect conclusions. This paper aims to develop a weighted ADQI to overcome the deficiency of the unweighted ADQI to make it more reliable for LCA uncertainty analysis.

Method

To improve the UWADQI approach, an analytical hierarchy process (AHP) is introduced in this research for estimating weighting factors in the ADQI aggregation process. An AHP??s pairwise comparison function is used to determine the weighting of each data quality indicator. Three common building materials of concrete, steel, and glass were chosen to validate the presented method.

Results and discussion

Using the published results from the statistical method as the benchmarks, it was found that the proposed AHP-weighted ADQI (AWADQI) method lead to better estimated probabilistic values of embodied energy intensity than the traditional UWADQI approach for the three building materials.

Conclusions and recommendations

In conclusion, using AHP to incorporate weighing factors into an ADQI process can improve the uncertainty estimate of embodied energy of building materials, and consequently, the method can improve the reliability of a building LCA.