The purpose of this paper is to explore the issue of the criteria of project success and the complexity of the subject in the context of environmental and nature conservation projects financed by European Union. The article presents various definitions of project success The article deals with definition and evaluation process of the project success as well as specific conditions of EU project management. Thematic evolution and trends in defining project success are presented through systematic review of literature on project management. The first part of the article focus on reviewing different approaches to the subject of criteria of project success, which is the crucial part of the proces. It is impossible to determine critical success factors (CSF) without deciding on the criteria of the project success. Project success definition is an important and complex project management issue. The success of the projects was considered for the last 50 years in a various ways and by different project management scholars. There is a consensus about the importance of this aspect for the project management practice. However, the project management in the context of EU-funded projects is still subject of further research, as this issue was not yet properly analyzed. The article presents the specific of the environmental and nature conservation EU-funded project judgement proces. The procedures and the scope of the formal and substantive assesment which is the part of selection procedure were described. The paper presents also how formal and substantive assesment criteria correspond with success criteria definitions created so far by the researchers. Moreover, the article analyses how existing asssesment criteria, precisely defined in EU programmes documentation and procedures, can be treated as EU project success criteria. The article presents also the most important challenges and issues in determining the set of success criteria based on assesment criteria set for regional operational programmes and Operational Programme Infrastructure and Environment for 2014–2020 programming period.

Underground spaces having features such as stability, resistance, and being undetected can play a key role in reducing vulnerability by relocating infrastructures and manpower. In recent years, the competitive business environment and limited resources have mostly focused on the importance of project management in order to achieve its objectives. In this research, in order to find the best balance among cost, time, and quality related to construction projects using reinforced concrete in underground structures, a multi-objective mathematical model is proposed. Several executive approaches have been considered for project activities and these approaches are analyzed via several factors. It is assumed that cost, time, and quality of activities in every defined approach can vary between compact and normal values, and the goal is to find the best execution for activities, achieving minimum cost and the maximum quality for the project. To solve the proposed multi-objective model, the genetic algorithm NSGA-II is used.