The article discusses the prospects and advantages of using QGIS for solving spatial planning tasks. Attention is focused on the strengths of QGIS compared to other geographic information system software and the programme’s potential to eliminate the monopoly position in the market by well-known geographic information system software manufacturers. Even though QGIS is open-source software, this software product is generally not inferior to expensive geographic information system software. At the same time, the advantages of QGIS include cross-platform, rich functionality, the ability to use different geographic information databases, and the ability to connect and integrate various plug-ins into the programme. Particular attention should be paid to the ability to independently write plug-ins for solving specific highly specialised tasks in the Python programming language and their quick integration into the QGIS software environment. Examples of QGIS software for solving specific spatial planning problems are given. The possibilities of using QGIS in solving the issues of settlement planning, territory management, land management and environmental monitoring are considered. The conducted research gives grounds to recommend QGIS for wide application by developers of project documentation, as well as by executive authorities and local self-government bodies for analysing cartographic and project materials in making management decisions. This approach will help create a competitive environment among developers of urban planning and land management documentation. After all, today, many specialists cannot afford expensive commercial licenses of well-known geographic information system software developers. And any legislative requirements that oblige them to use them in practice lead to monopolisation of the market for these services by individual enterprises. At the same time, it has been proven that using the open-source geographic information system software QGIS will not lead to a deterioration in the quality of project documentation. The programme can ensure the proper quality, accuracy and interoperability of design and mapping materials created with its help and solve a wide range of tasks in spatial planning.

Recently, the opinion has been expressed that the phasing of the processes of preparation of territorial planning documents, depending on the institution that administers it, hinders the processes of preparation of territorial planning documents by established procedural actions. The aim of the article is to evaluate the impact of the efficiency of the administration of territorial planning processes on the development of territories. The object of the research is the complex and special territorial planning documents prepared in the territory of Pagėgiai municipality. Pagėgiai municipality was chosen because the preparation of planning documents in the municipality has slowed down recently, therefore it is important to assess the efficiency of administration of the prepared territorial planning document processes, possible impact on further territorial development, and provide recommendations to ensure more efficient and faster territorial development. During the research, it was established that during the period between the years 2010–2020 only 1 state-level territorial planning document was registered in the territory of Pagėgiai municipality (i.e. 0.69% of those registered in the Republic of Lithuania and 14.29% in Tauragė County). 7 (i.e. 0.52% of those registered in the Republic of Lithuania and 18.42% of those registered in Tauragė County) were registered in the municipality at the municipal level. Territorial planning documents were registered at the local level (i.e. 0.22% of those registered in the Republic of Lithuania and 5.4% in Tauragė County). The analysis of the processes of the prepared planning documents and the interviews of experts revealed that the planning procedures performed by the administering authorities are inefficient: not all the administering authorities consistently carry out the assigned procedures, delay or evaluating the planned decisions within the legal deadline. According to experts, the reason for the inefficient performance of procedures is the lack of human resources in the administering institutions or their inadequate competence. As a result, the improperly performed procedures of territorial planning documents have a negative impact on the planned territory, slow down its development, or the most suitable possible development direction of the planned territory has not been assessed. After performing a multi-criteria analysis of the prepared territorial planning documents, it was established that in the period under review, the most effective document of complex territorial planning was prepared in the territory of Pagėgiai municipality — “Adjustment of the detailed plan of the prepared territory in Vilniaus st. 16 A, Pagėgiai”. The rating indicator was 0.0806. The document of complex territorial planning “Adjustment of Pagėgiai city comprehensive plan” stood out with the lowest efficiency, the rating indicator was — 0.0676.