  Information System Quality (ISQ) management discipline requires a set of
assessment mechanisms to evaluate external quality characteristics that are
influenced by the environmental parameters and impacted by the ecosystem
factors. The present paper suggests a new assessment oriented model that takes
into consideration all facets of each external quality feature. The proposed
model, named RatQual, gives a hierarchical categorization for quality. RatQual
is designed to quantify dependent-environment qualities by considering
internal, external and in use aspects. This model is supported by a tool that
automates the assessment process. This tool gives assistance in quality
evolution planning and serves for periodical monitoring operations used to
enhance and improve information system quality.
