Steel plate shear walls with beam-connected web plates (B-SPSW) are considered effective configurations in alleviating the tension field effects on vertical boundary elements through the detachment of web plates from them. It is critical to establish robust analytical models while investigating these setups. The plate-frame interaction approach (PFI), initially introduced for traditional SPSWs, is a widely used model that separately analyses the web plate and the surrounding frame. The purpose of this study was to propose a modified PFI (MPFI) method for B-SPSWs in light of their unique properties. Additionally, the buckling phenomena were thoroughly explored to justify thicker plates in the aforesaid configurations. Finite element models were created to determine the accuracy of the newly generated MPFI method equations for B-SPSWs. The numerical specimens were chosen to illustrate a variety of practical uses for these systems. Finally, the MPFI accurately predicted the strength and stiffness of the case studies, and significant overlaps between the MPFI diagrams and the numerical backbone curves were detected. The ratio of MPFI shear capacity to shear yield strength was found to be between 0.93 and 1.04 in numerical specimens. However, it was determined that the use of thick infill plates resulted in the premature production of plastic hinges in the frame, hence reducing the shear capacity envisaged.