In an attempt to increase the competitiveness of small organizations, the ISO has developed a standard, the ISO 29110. Due to its recent emergence, the high rates of the unknowledge about its implementation and associated costs, it is still difficult for small organizations to take this standard into practice. In order to reduce the conceptual gap, in this paper has been purposed a software process model (UP-VSE) bassed on the Unified Process, which implements the requirements engineering practices of ISO 29110-5-1-1 in order to companies can have an illustrative and reusable case allowing them to increase the standard interpretation and implementation. This proposal has been empirically evaluated defining PRODIGIA software process in the context of a research and development group of industrial automation.