The ongoing digital transformation raises the need to address the evolution of legacy systems in response to integration requirements. One challenge is integrating sensors and actuators (and their controllers), modeled as IoT elements, and linking them to data analytics, management, and operations decision support functions or processes. Since legacy technology systems follow proprietary architectures, their integration into open service-oriented architectures (SOA) requires a strategy that maintains a high degree of reliability. This paper presents the strategy adopted to integrate legacy software in an open SOAto managean agri-food silos infrastructure. This approach follows the Informatics System of Systems (ISoS) idea and is based on the ISoS framework. A reference implementation concept is used to validate the (re)construction of legacy systems and make them ready for collaboration with agro-industry business partners considering their Enterprise Resource Planning.