Modeling – Modeling constructs abstract description that is amenable to interpretation [4]. It evokes the details that were missed in the initial elicitation. There are different categories of RE modeling approaches [4]. For ES development, we need to focus in data modeling, domain modeling and analyzing requirement analyzing model. Knowledge in ES is data and it is layered [13]. Therefore, we need to organize data and details gathered during initial elicitation so that it can be understood by all stakeholders. Regarding to this, we need to take times and effort to model the data in order to make the requirements clear