GMAA: A DSS Based on the Decision Analysis Methodology - Application Survey and Further Developments - Efficient Decision Support Systems: Practice and Challenges from Current to Future - page 270

sensitivity analysis should be carried out to output further insight into the
recommendations.
First, all the intervention strategies were non-dominated and potentially optimal, i.e., they
were not dominated by any other strategy and best-ranked for at least one combination of
the imprecise parameters, i.e., weights, component utilities and strategy impacts. Thus, we
could not discard any of them from further consideration.
Then, Monte Carlo simulation techniques were applied. The response distribution weights
option was selected, i.e., attribute weights were randomly assigned values taking into
account the weight intervals provided by the DMs in weight elicitation, see Fig. 3. Fig. 5
shows the resulting multiple boxplot.
Fig. 5. Multiple boxplot with response distribution weights
Only two intervention strategies were best ranked for at least one combination of weights,
Potash and Food Ban , but the worst classification for both was second and seventh,
respectively. Moreover, the mean classifications were 1.065 and 3.785, respectively,
indicating that the intervention strategy that should be definitively recommended was
Potash .
3.2 Selection of a supplier for cleaning services in an underground transportation
company
The GMAA system was also used to select a supplier for cleaning services in a European
public underground transportation company (Jiménez et al., 2007).
From a cost management perspective, the cleaning service represents a sizeable part of the
operating costs of an underground transportation service, accounting for close to 10% of
total annual operating expenses. Inherent service intangibility, heterogeneity and
inseparability greatly constrain service acquisition and management (Zeithaml et al., 1990).
For the purpose of determining the most economically advantageous suppliers, several
conflicting criteria were taken into account simultaneously to provide the most relevant
information about what other factors, in conjunction with prices, to apply during the award-
of-contract process, like delivery conditions and human resources, technical merit and
resources, quality control procedures, etc., according to the public procurement policies and
legislation for national and European public organizations. These criteria were compiled as
a result of a team effort, including procurement and technical experts from the