The development of Information Systems today faces the era of Big Data. Large volumes of information need to be processed in realtime, for example, for Facebook or Twiter analysis. This paper addresses the redesign of NewsAsset, a commercial product that helps journalists by providing services, which analyze millions of media items from the social network in realtime. Technologies like Apache Storm can help enormously in this context. We have quantitatively analyzed the new design of NewsAsset to assess whether the introduction of Apache Storm can meet the demanding performance requirements of this media product. Our assessment approach, guided by the Unified Modeling Language (UML), takes advantage, for performance analysis, of the software designs already used for development. In addition, we converted UML into a domain-specific modeling language (DSML) for Apache Storm, thus creating a profile for Storm. Later, we transformed said DSML into an appropriate language for performance evaluation, specifically, stochastic Petri nets. The assessment ended with a successful software design that certainly met the scalability requirements of NewsAsset.