  The article proposes a model for the configuration management of open
systems. The model aims at validation of configurations against given
specifications. An extension of decision graphs is proposed to express
specifications. The proposed model can be used by software developers to
validate their own configurations across different versions of the components,
or to validate configurations that include components by third parties. The
model can also be used by end-users to validate compatibility among different
configurations of the same application. The proposed model is first discussed
in some application scenarios and then formally defined. Moreover, a type
discipline is given to formally define validation of a configuration against a
system specification
