Now more than ever, public organizations are changing their role from developers to acquirers of software products and services. To accomplish the principles of transparency and economy that these organizations must preserve, they have adopted the building engineering practice of issuing call for tenders. In order to apply, prospective software suppliers need to analyze these documents, make the decision of participation and to confront the process of building a software offer. This process involves a set of software engineering practices that, up to now, have remained unexplored in terms of suppliers' risks, mitigation strategies and decision variables. In this paper we present a qualitative research based on the focus group technique that provides some important clues to understand this process and define an initial set of variables to be further explored. Conclusions remark on the worth of field study and the next step on quantitative research using found variables.