When implementing enterprise software packages, the single most common reason for dissatisfaction, or even total failure, is a “data model mismatch.” That’s a bold statement, but it is backed up by the speaker’s 40 year consulting career and many “project recovery” assignments. In those cases, an organisation has spent tens or hundreds of millions or even billions of dollars (or euros) on implementing purchased software, and it simply doesn’t work or works so poorly the organisation is worse off than before. This presentation will share the common factors in these failures, and also some success stories and how data modelling fits in helping solving these problems.