Owing to their non-fibrous and environmental-friendly feature, micro-perforated panel (MPP) absorbers are widely used in various architectural, industrial and environmental applications for providing efficient sound absorptions. When used in compact mechanical systems, however, evidences show that their sound absorption performance is strongly affected by the surrounding vibroacoustic environment. While posing challenges in understanding the underlying physics on the working mechanism of MPP, it also leaves rooms for the better acoustic design of such systems through possible optimization at the same time. This paper presents a comprehensive review on some of our recent studies on MPPs, associated with their modeling, analysis and optimization in complex working environment. Through examples, the versatility and efficiency of the proposed modeling tool, as well as the underlying physics behind MPPs are demonstrated. Typical examples include elementary cavity-backed MPP absorbers, noise control inside enclosures, duct silencers, cascade separations with application to the design of ventilation windows.