The present disclosure provides a system and method for dynamically defining a specific input pin of a management controller (e.g., a baseboard management controller (BMC)) of a server system in response to a new device being plugged into the server system. The new device comprises one of a power supply unit (PSU), an automatic transfer switch (ATS), or a battery backup unit (BBU) of the server system. In some implementations, the PSU, the ATS, and the BBU are modularized into a plurality of ATS modules, a plurality of PSU modules, and a plurality of BBU modules, respectively. Each of the plurality of ATS modules, the plurality of PSU modules, and the plurality of BBU modules has substantially the same physical size.