Public administrations are under an increasing pressure to improve their effectiveness and efficiency usually with the means of new IT solutions. However, IT solutions do not necessary bring the desired results if being based on ineffective processes. By considering these, we performed a project in public administration sector, whose aim was to provide precise technical specification for a new IT system based on redesigned business processes. As a result, a 58 pages-long process specification was created, consisting of nine processes being specified and modelled from several viewpoints. This paper evaluates the applicability of (novel) technologies and approaches used in the specification. Additionally, lessons learned and challenges, related to activities and process outcomes, are presented and critically evaluated.