Methodologies, systems, and computer-readable media are provided for monitoring object locations on a shelving fixture. An electronic detection device includes a first motor for winding and unwinding a first line and a second motor for winding and unwinding a second line. A controller can control the operation of the first and second motor and the electronic detection device is suspended from the first and second line behind a shelving fixture. When the first and second motor wind and unwind the first and second line, the electronic detection device moves to an expected location of an object on a shelving fixture. The electronic detection device also includes sensors that can determine an identity of the object and the quantity of the object on the shelving fixture.