Data are increasingly important in many industry sectors. Plants managers often do not realize the importance of having a huge amount of data available. The implementation of Key Performance Indicators (KPIs), based on these data, can be really helpful to give to the managers an overview of the real behaviour of a plant, in order to improve its efficiency and respect the local limits. Python has become one of the most appreciated programming languages in data mining, as well as in decision tree algorithms development, due to its specific libraries for data handling. Combination of different sensors data, plant managers and operators feedbacks and a deep industrial process knowledge, is a great set of skills to get KPIs tailored on plants characteristics and management needs. Operational use cases of KPIs and decision trees algorithms developed in Python are presented, as demonstration of how different engineering skills mixed with the power of Python programming could really boost the work quality and the customer satisfaction.