Planned maintenance of installation systems is performed at the diagnostic-X-ray facility, which is located within the main building of the General Hospital Pula. Every hospital is one of the most necessary institutions for the life of every human being. The General Hospital in Pula is the only institution of its kind in a very large area, which increases the importance of the functionality of this facility. On-site installation systems are some of the key elements of the functionality of any facility. The functionality of installation systems requires proper and timely maintenance for which planning is mandatory. According to the obtained knowledge about the condition of the facility, with the help of the project, project task and efficiency analysis, an approach to solving the problem with planned maintenance is planned. The condition of the installation systems was analyzed including all irregularities, damages and malfunctions. The solution to the problem is approached by planning the reconstruction of the installation system at the diagnostic facility where the maintenance of installation systems is required. Reconstruction is based on solving the problems indicated in the terms of reference on each installation system individually, which overall contributes to the availability of the hospital facility. The planned maintenance was realized by performing reconstruction works. The availability of the hospital building was again achieved by the completed reconstruction and the entire hospital building was enabled to continue uninterrupted work. The smooth operation of the hospital is very important for the entire region of Istria because the hospital is an institution that is necessary to improve the quality of life.