Business-IT alignment (BITA) remains a challenging topic for enterprise architects. This is notably the case of operational BITA that focuses on the alignment between business processes and IT applications. In this context, a major challenge is to determine the level of alignment between these Business and IT layers. Existing approaches already propose to assess this alignment, but they are often context-specific. Moreover, no approach intends to combine various assessment means for a more in-depth evaluation of the alignment. As a solution, we propose an alignment assessment approach combining different means (metrics, consistency rules, and anti-patterns). We also provide a methodology that integrates this approach by relying on an established cartography (expressing the current state of alignment) and proposes a corresponding redress step. This cartography is composed of Business and IT models, and of explicit links between them. Both the proposed methodology and assessment approach are illustrated on two case studies for validation purposes. In the reported experiments, we considered six metrics, two consistency rules, and four anti-patterns.