Hi,
u have to first convert the EDI file into Idata values object using convertToValues.and also u have to define the flatfile schema in developer .then u have to create the document type from this schema.
then map your EDI values data to corresponding flatfile document type.finally use convertToString service , by passing these, flatfile values and schema as inputs , you will get your flatfile.Wmflatfile, and EDI user guide will help you lot on this procedure.
HTH,
Rao.
#Integration-Server-and-ESB#webMethods#edi