The relationship between environmental input and output indicators by the robust fitting method

Environmental protection has aroused much public concern in recent years. Environmental management systems (EMS) have been advocated for all economic sectors. The construction industry contributes to environmental destruction by generating pollution and is by no means exempt from EMS. The greatest obstacle, in carrying out EMS, is the lack of objective performance evaluation criteria. In 1999, ISO 14031 environmental performance evaluation (EPE) was introduced for assessing the environmental performance related to management and operational systems. Unfortunately these measures are not adopted in the construction industry in some parts of the world, including Hong Kong. However, there have been a number of economic sectors implementing EMS and EPE including electronic engineering, telecommunications, mineral exploration, oil and gas industries and power generation. The construction industries reluctance is due to the self-initiation nature of the scheme lacking any external stimulus and the thin profit margins achieved by most construction firms. The high investment cost of the scheme deters contractors from the implementation of it although the application of EPE does offer many benefits. This paper attempts to develop a series of input (EOI) and output (EPI) indicators for EPE and measure their relations by using a robust fitting method. The results show that the defined EOIs correlate strongly with EPIs. Therefore, EPE can help in identifying areas for continuous improvement, and can provide an early indication of the environmental performance for an organization.