The presented effort is the extract of a composite work. Primarily to model a dc servo-system within the available framework through observed data. The observed data of the hardware are classified as input and output samples measured at discrete instants of time and collected as an array of data for finite duration. Several input-output data sets are collected and processed to find out the model of the dc servo motor through System Identification Tool Box of MATLAB, a Graphical User Interface (GUI) based approach. The fitness of identified model is checked every time new data set is applied to choose the best fitted model. Secondarily to demonstrate in steps the ways of design and implementation of Internal Model Principle (IMP) & Finite Dimensional Repetitive Control (FDRC) based Proportional Integral Derivative (PID) controller for the plant. A similar test has been made with the system using conventional PID control. Finally, a valid comparison is carried out to show advantage, disadvantage or limitation of applied control schemes.