Reliable management information is invaluable for policymakers and advisers to make informed policy decisions. Depending on the information needs of the policymakers and the characteristics of the data required, different approaches exploiting different ways to process data from multiple sources, may be used. In this chapter, we describe three information systems currently in use in the Dutch criminal justice system. The first system is based on a dataspace approach and uses aggregate data to provide a view on the current state of the criminal justice system. This is particularly useful for evaluating current policy and monitoring the implementation of new policy. The second system utilizes a data warehouse to integrate individual level data and look back to older cases. Therefore, it is suitable for evaluating policy. Finally, the third system exploits time series data to forecast the capacity needed in the near future. This allows for planning new policy and monitoring its implementation. Based on our experience with developing and implementing such systems and their use in practice, we lay down a list of guidelines for developing management information systems in the public sector. These guidelines also address issues like data quality, misinterpretation, and privacy protection.