This paper presents a semi-automated method for evaluating SOAs called SOAQE, correcting defects observed so far with existing methods such as lacks of pertinence and accuracy for evaluation results. SOAQE takes as a starting point the McCall model, describing software quality, which led to an international standard for the evaluation of software quality (ISO/IEC 9126-1, 2001). This model is organized around three types of quality attributes (factors, criteria and metrics). The SOAQE method consists in decomposing the whole architecture and evaluating it according to the McCall model, i.e.a list of quality factors arising from business needs grouping criteria composed by metrics. Our experimentations led us to quantify numerically a first determining factor for SOAs, the 'dynamism' and some attributes of its structure: namely the 'loose coupling' criterion and its constituent metrics ('physical, semantic and syntactic').