we want to find the best
configuration (vector) for each (new) environment.
However, this is very difficult, if not impossible, since the
adaptation space of Architecture IV systems contains an
exponential number of configurations. To illustrate, the
simplest configuration of an Architecture IV system could
be [THm, THs,DL,DT], then the size of the adaptation
space is domain(THm) × domain(THs) × domain(DL) × domain(DT), which is actually huge. Moreover, we face
conflicting reconfiguration criteria, that is, healthiness and
cost conflict with each other, and integrity and availability
conflict with each other. Therefore, we envision the
problem of finding the best system configuration under
multiple conflicting criteria a NP-hard problem.