The objective of this procurement procedure is to procure the services/products described in these procurement documents and to select an experienced contractor capable of designing, implementing, and operating the further development of the City of Zurich's greenhouse gas (GHG) emissions monitoring system in close collaboration with UGZ. The project will commence with the first implementation increment, which comprises the data collection, solution design, and delivery of Release 1. Based on this initial release, further implementation increments and system enhancements shall be designed, implemented, and operated iteratively in accordance with the priorities defined within the project. In this context, it is of paramount importance to UGZ that the selected contractor assumes overall responsibility for the management and coordination of the project in the role of a General Contractor (GC) and provides comprehensive support to UGZ throughout the project. UGZ has only limited ICT resources available and therefore relies on the contractor to take overall responsibility for project delivery.