The paper of the IOT in the connected factory and IOT sensorisation from a chemical plant. The IoT is one of the technologies that are changing our lives, being able to allow us to interact with different objects in our environment, from vehicles, homes, industries, cities to critical infrastructure such as power grids, gas and water supply, among others everyday-life areas. In the industry, IoT has become one of the key enablers to encourage factories to the production model driven data. IOT sensors, measuring devices, reading data, Dimensions, Big Data, Business Intelligence, Software, Industry 4.0, Energy Efficiency, Environmental Management. Description of a real case of IoT sensing of a chemical plant serving the main criteria for industry 4.0. From the design phase to implementation, the requirements of each phase with the problems and solutions that were applied are detailed. Special attention to data collection and subsequent operation for the areas of business strategy through dashboards.