One of the main problems in high-tech enterprise management is the issue of integrated logistics support of production and service, which is not considered an independent methodological problem by manufacturers. The article describes the baseline architecture of the information system based on the CALS conceptual model (Continuous Acquisition and Lifecycle Support). Research into ILS tasks and reference architecture components made it possible to propose a reference architecture model of the unified ERP II system for integrated logistic support. Two main approaches to developing integrated systems were considered while constructing the information system architecture: mono platform and poly platform. Poly platform systems integration is used as a method of constructing the target architecture of a unified information system for information support life cycle product (with all the necessary improvements). A gap-analysis of the transition from the baseline to the target architecture, reflecting the main stages, is provided. The proposed reference architecture model of an information system represents a possible solution that provides support for solving not only the integrated logistics support problems but also the core tasks of the enterprise: supply chain management, resource planning, customer and supplier relationship management. A reference model of the system architecture was built with due regard to integration tools for information exchange in a single information space between all the subsystems. The proposed model is based on a single service-oriented platform and the Integration Bus which allows connecting systems of different manufacturers. Each system is discussed in detail. The key functions and tasks of each system (general and service ones) are described.