Purpose - The purpose of this paper is to formally verify the composition of web services to reduce inconsistencies in software architectures. Design/methodology/approach - In order to check the web services composition, the authors use a model-driven engineering (MDE)-based approach and to achieve the formalization of web service composition in ACME and check the consistency of this composition, the authors introduce the pattern mediation to formalize web services composition with the ADL ACME, using the concept of architectural style of ACME. Subsequently, a scenario shows how this style can be used in ACMEStudio to detect inconsistencies. The example shows a web travel organization application. Findings - The authors ensure reliability defined through non-functional properties. To do so, use ACME was used to check assembling consistency of web service composition. In a second part, a SWC2ACME tool was designed and implemented to check if the web services meta-model conforms to ACME model. Originality/value - The paper describes a framework which has proven to be useful to ensure a safe design and execution of software architectures, specifically web services composition