Business-IT Alignment (BITA) is an important mean of evaluating the performance of IT systems operating within a business organisation. The software architects’ need for representing, analysing and interpreting the alignment situations remains among the main challenges. Despite different initiatives in the last two decades, available solutions remain too diverse and limited. As a consequence, more methodological guidelines are still needed to improve the support for BITA. In this paper, we address Core Operational BITA (COBITA) as a subset of BITA which targets the operational integration of business and application artefacts. To this end, we first propose two types of COBITA links between the business layer and the application one. We propose then an approach for establishing these links and evaluating them. The objective is to provide indicators for domain experts and software architects to assess the quality of the alignement between the two layers. We decided to choose Archimate, a standard language, to model the business and application layers. Then, we specify the two types of COBITA links to establish a mapping between the business and applications layers. Finally, we rely on the obtained cartography to evaluate the alignment via a set of proposed metrics and consistency rules. An initial version of the approach has been implemented in the Archi tool, and we experimented with it on the SoftSlate system.