The subject of this research is the integrated security systems and the processes of their continuous improvement during the lifecycle. The goal lies in examination of the problem of systematization of lifecycle processes of the integrated security systems and formalization of their lifecycle model, taking into consideration the available practices of building security systems. The effectiveness of complex system support processes is first and foremost determined by the accurate identification of management goals and objectives, which requires an the lifecycle model adequate to the controlled object. Since the integrated security system has the characteristics of both, capital construction (engineering networks) and technical system (integration platform), the question of improvement of the lifecycle model is relevant. The main research results are as follows: substantiation of the problem of systematization of lifecycle models of the integrated security systems; analysis of the approaches towards their standardization, and substantiation of lifecycle model of the integrated security systems based on the system accounting of conducted operations. The novelty of the proposed model lies in the improvement of reference models of the integrated security systems by taking into account the entirety of reconfiguration and modernization operations. Description is given to the problem of systematization of lifecycle processes of the integrated security systems, which occurs due to the possibility of their classification as different groups of the complex systems. The offered lifecycle model of the integrated security systems through systematization of regulatory requirements is an attempt to acquire a non-contradictory list of measures in creation and operation of the integrated security systems. The results of this research can be used in practical activity of the employees of onsite security service in the context of development of the integrated security system. The implementation of the offered lifecycle model of the integrated security system in the processes of their development would allow systematizing the structure of processes, arranging the functions and activity of the departments on the continuous logistic support of the integrated security systems, and ensuring their consistent improvement.