Business-to-business (B2B) electronic commerce is very much about relationship-building and bringing about mutual improvements for both trading partners. In the B2B context, the expected economic "net-value" is a primary concern when considering a deployment in an electronic commerce system or not. The main purpose is to suggest some issues to consider for possible modications of the PENG method. Firstly, this empirically grounded method for assessing an organization's economic "net value" from an IT investment is described. Then a review of some of the IS evaluation literature, structured along Pettigrew's contextual framework, is presented. In the concluding part of the paper some of the suggested modifications of the PENG method is presented