: In this paper we explain how we have integrated the functionalities of a constraint management system and a temporal data base system to enable a model-based control of systems that exhibit large delays between the events characterizing its behaviour. Examplesof problemswhere our approach is appropriate, include the monitoringand controlling of complex and geographically distributed systems. Such applications require a robust modeling of the behaviour of the systems, in terms of causal relationships among its state variables, and the handlingof temporaldelays that mayspan between an event and its causal in uences all over the system. Our approach as been applied to build a KBS for assisting heating central operators to optimize the e ciency and profitability of the heating process.