IMWZ is an application for management of system infrastructure maintenance. It offers a trade-off between easy to use and effective user interface done in Microsoft Excel and a complex back-end mathematical model of infrastructure maintenance implemented in C#. System structure is composed of different objects like roadways, sewage pipes, bridges, tram railways, water pipes, gas pipes, and electricity cables. A unique feature of the application is that multiple objects can be considered as a single section subjected to maintenance in order to achieve the goal of optimal maintenance policy, the goal which states that the long-term maintenance cost of the system should be minimized. As a final result, IMWZ offers different kind of reports like a valuable system maintenance plan for some future time horizon (typically 10 years), and mean state and state distribution of subsystems and object types during time horizon of prediction along with direct and indirect cost of maintenance.