In the last few years, the Smart Grid concept has gained ground in the power utility scope. However, due to its multidisciplinary character (involving a stack of technologies) it is very difficult to assess the overall project success. Due to this a metric is required. In this paper, the authors review the existing metrics and (based on their experience within the Smart Grid demonstration project "Smartcity Malaga"), propose a new approach of business intelligence to bring about a new metric or set of key performance indicators for its rating. An advantage of this metric is its capacity to assist in this task. Its usefulness is also complemented with a planning tool that enables us to assess the effects of each technology under potential scenarios. This information is useful for planning projects, allowing us to make the most appropriate decisions each moment. Ultimately, this usefulness is clearly demonstrated through two case studies. (C) 2014 Elsevier Ltd. All rights reserved.