A system and method for defining MES interface to process a transaction between a server and a client from an XML base, the transaction between the server and the client based on a communication protocol, the server having an MES, the system for defining the MES interface comprising an IDL file for executing a plurality of service objects of the MES, an XML tag set file, wherein the XML tag set file uses XML for defining interfaces of the plurality of service objects and an XML schema file, wherein the XML schema file is within a web server for validating an output content generated by executing IDL file and the XML tag set file, wherein the XML tag set file is adapted to serve at least one argument of the plurality of service objects within the IDL file.