An apparatus includes a drop unit, a transfer unit and a position adjusting unit. The method includes compiling a computer program. The master station E requests to hand over a master station capability to the terminal device G. After reaching full recoil, the front and rear slides return to their resting positions. The roller of the first link rollably engages a surface on the third link when moving in and out of the clamped position. A builder prepares a computerized model of the call center using the call center layout tool.