  Multi-Agent Systems (MAS) promise to offer solutions to problems where
established, older paradigms fall short. In order to validate such claims that
are repeatedly made in software agent publications, empirical in-depth studies
of advantages and weaknesses of multi-agent solutions versus conventional ones
in practical applications are needed. Climate control in large buildings is one
application area where multi-agent systems, and market-oriented programming in
particular, have been reported to be very successful, although central control
solutions are still the standard practice. We have therefore constructed and
implemented a variety of market designs for this problem, as well as different
standard control engineering solutions. This article gives a detailed analysis
and comparison, so as to learn about differences between standard versus agent
approaches, and yielding new insights about benefits and limitations of
computational markets. An important outcome is that "local information plus
market communication produces global control".
