This paper proposes a concise methodology of Field-Oriented Control (FOC) with parameter variation analysis for Interior Permanent Magnet Synchronous Machines (IPMSM). Initially, the IPMSM model is revisited. The approach for modeling an IPMSM is initially presented. Then, a step-by-step procedure for designing a vector controlled strategy is presented. The formulation is based on a dq-rotating reference frame which is aligned with the rotor shaft position. One simple decision that makes the methodology presented to be different from traditional ways for such controller is that the current controller is designed on time-domain based on desired time constants, while the speed control is formulated based on a frequency response domain framework. The proposed hybrid approach allows accurately tuning the parameters of the Proportional-Integrator (PI) controllers of the current and speed control loops. It is also performed a parameter variation analysis to enhance the proposed methodology. The validity region for the design procedure is presented where for any wide speed variation of the machine there is a scheduling of loop gains. The most noticeable advantage of the methodology in this paper is to make a fast, reliable and accurate technique for implementation IPMSM drive systems. Hardware-in-Loop (C-HIL) with external DSP based digital control. Results from a Controller Hardware-in-Loop (C-HIL) with external microcontroller are presented. The comprehensive design approach is verified under two different IPMSM parameters and the results showed its effectiveness.