Municipal solid waste incineration (MSWI) fly ash (FA) can be a secondary resource of valuable components. The recovery of metals (Zn, Pb, and Cu) from MSWI FA is possible using the FLUWA technology. A metal-rich filter cake, the product of FLUWA, can be utilized as a secondary resource of metals in smelters. For industrial utilization, the recovered filter cake should fulfill certain technical criteria and be produced in a sufficient amount. Additionally, it is important to evaluate and quantify the environmental impacts of the applied technology. The paper aims to evaluate the current set up of the FLUWA technology by statistical entropy (SE). The results show that the SE due to the use of the FLUWA technology for metal recovery from MSWI FA is staying more or less constant even though the SE is partially rising due to the individual process steps. The steps with the highest influence on the SE are extraction (SE is rising), and sedimentation and filtration (SE is decreasing). It can be shown thateven by raising the efficiency of metal extraction (at the moment, for Zn ca. 50% but for Cu and Pb only nearly 0%), the SE after process extraction would get higher. However, in the end, this would lead to a \nlower SE of the final outputs of the FLUWA technology.