A today's challenge in civil engineering is to plan maintenance activities on network of infrastructures. In this field, communication problem between engineers and managers represents a very relevant issue. In effect, to allow an efficient and informed optimal decision process, it is of paramount importance that engineering outcomes are understandable by owners and managers. Pursuing this scope, the queueing theory could be a very efficient tool to express the networks performance and availability measures in a compact and analytic way. This approach could improve the communication between engineers and managers, also in view to easily compare and optimize maintenance plans. Focusing the attention on the German network of waterways, whose infrastructures are affected by aging problems and require additional maintenance, a significant case study is developed, in which we demonstrate how performance and availability measures can be implemented for planning maintenance intervention on a network of locks. The ultimate scope is to shift the current maintenance practice towards a more mature maintenance management system, in which the waterways networks morphology and the amount of traffic are also considered.