Autor(es):
Duarte, António A. L. Sampaio 
; Rodrigues, Gisela Maria da Costa ; Ramos, Rui A. R.
Data: 2009
Identificador Persistente: http://hdl.handle.net/1822/18209
Origem: RepositóriUM - Universidade do Minho
Assunto(s): Water supply systems; Performance indicators; Multicriteria analysis; Weighting methods; Service quality index (GISEQ)
Descrição
Water supply systems are a structural part of public utilities and as such are vital to the general well-
being, public health, safe drinking water use, economic activities and environment protection. Being the water
“market” a natural monopoly, regulation must, mainly, protect the interests of the user, based on a
benchmarking strategy that promotes the quality of the water supply service and assuring the balance of the
ruling tariffs.
Due to the complexity of service quality assessment, the use of performance indicators is essential as a means
to provide a measure the utility’s effectiveness and efficiency. In Portugal, this task is conducted by an
independent public entity, which has defined a specific set of performance indicators. Currently, the adopted
system does not provide a quantitative and integrated evaluation leading to an overall ranking of utilities’
performance and sustainability.
This work aims to contribute to the improvement of the Portuguese assessment system, through the
development of a complementary methodology that defines a global index of service quality (GISEQ) for a
given water supply utility, based on a new application of multicriteria analysis. The GISEQ value is calculated
as a combination of the normalized scores of each performance indicator, previously aggregated in three main
groups: protection of user interests, sustainability of the utility and environmental sustainability. In this
proposed methodology, each one of the selected performance indicators represents a criterion to be considered
and judiciously weighted. An innovative approach to weights definition was performed as well as a sensitivity
analysis of different weighting methods on water supply utilities’ ranking positions.
