Energy efficiency is crucial for the sustainable operation of all industrial and urban sectors. However, practicing engineers have seldom access to open-source tools that can readily evaluate and compare scenarios in terms of energy consumption, cost, and environmental impact. In this work, a web-based tool called ROSMOSE is proposed for assessing the energy efficiency of systems and comparing available integration options. The ROSMOSE engine has been conceived as a high-level reporting language used to exploit the capabilities of the OSMOSE platform. This platform is an optimization framework that takes input process data and uses it to compute and graphically represent minimum energy requirement, pinch temperatures, and grand composite curves of industrial processes. The tool is then used to select suitable technologies that satisfy the energy demands, while minimizing costs. The Rmarkdown engine on which it is built allows the integration of various software and tools, such as database handling, process modelling suites, and optimization solvers, along with data visualization and reporting into any kind of format. ROSMOSE tool can be made available for the scientific community and industrial partners. As a case study, this paper discusses the application of ROSMOSE for the energy integration and total site optimization of a dairy process consisting of milk treatment, cream, and cheese production. Other integration options, such as heat pumps, biogas, and soft drinks production, are proposed to enhance the process economics and reduce environmental impact. As a result, 70 - 75% energy savings and up to 90% CO2 emissions reduction are identified.