Obtaining a measure of the trustability of a system in an open environment is a dif?cult task since trust concepts involve different quality criteria including non-technological aspects. Quality criteria and, above all, security mechanisms are commonly characterized by means of a set of statements making part of a policy. We are working on an evaluation methodology allowing automatic management for semi-formal policies and in this paper we propose a Trust Manager architecture (TruMan) enabling our methodology and an implementation of such architecture. We also present a proof-of-concept case study where Tru- Man is adopted in the context of Service Oriented Architectures.