This article discusses the requirements for the integration of information systems in a united information environment of an industrial enterprise. Compliance with these requirements allows you to minimize the loss associated with configuring integrated systems in a common system. This integration is based on the subsystems available at the enterprise that operate in the information infrastructure. The principle of information compatibility of subsystems is shown as the intersection of the set of data coming from the source subsystem to the recipient subsystem. The levels of necessary support for the components of subsystems for reliable, uninterrupted and safe operation of a united information space are considered. Describes the characteristics of the necessary work on maintenance and configuration of individual subsystems to prevent emergencies in the entire system as a whole. Reliability indicators of the solutions used to create the infrastructure subsystems are presented. The factors of the order of interaction between the personnel of subsystems and the personnel of the automation object are determined.