United Nation’s Centre for Trade Facilitation and Electronic Business (UN/CEFACT) is an e-business standardization body known for its work on UN/EDIFACT and ebXML. One of its on-going work items is the UN/CEFACT Modeling Methodology (UMM) for modeling global choreographies of B2B scenarios. The work on UMM started in 1998 and has improved since then by contributions from participating organizations, such as RosettaNet, SWIFT, GS 1. Today, all new UN/CEFACT standards for data exchange scenarios must be backed up by a corresponding UMM model. In this paper, we revisit the UMM version 1.0 that is defined as a UML 1.4 profile. We introduce the main concepts of UMM and elaborate on the strengths and weaknesses of UMM 1.0. Being the editorial team of UMM, we have made improvements to UMM, which will be released shortly as a new standard version. Thus, we elaborate on the new concepts of UMM 2.0 that are further illustrated by means of a simple example.