Abstract In today’s automotive industry, the A/C (Air-conditioning) system emerging into a high level of technological growth to provide quick cooling, warm up and maintaining the air quality of the cabin during all-weather conditions. In the HVAC system, TXV (thermal expansion valve) plays vital role by separating the high side to low side of vapor compression refrigeration system. It also regulates the amount of refrigerant flow to the evaporator based on the A/C system load. The HVAC system bench laboratory is used to conduct the test at different system load conditions and outputs from the tests are evaluated during the initial development stage to select the right TXV in terms of capacity and Superheat set point for a given system. This process is critical in the developmental activity, since the selected TXV was used to build the mule cars for initial assessment of the system performance. The TXV tuning is conducted in system bench lab using defined test load cases which is developed using factorial combination of given input boundary conditions and tests were conducted based on that. In this paper the major focus is laid on using DFSS methodology to identify the potential importance of each system parameter, identify the bench test boundary conditions which are critical for TXV set point decision making and understand the internal stake holder’s requirement. The whole process started with conducting the personal interviews with internal stakeholders and suppliers to collect the raw voices of customers. The DFSS tools were used to develop robust concept such as voice affinity, House of quality (HOQ) Pugh Matrix, and Function tree diagram etc. These raw voices from the interviews are then translated into most important voice and mapped with the current process using HOQ (house of quality) approach. The main purpose of house of quality is to derive the measurable targets to meet the customer requirement. This study helps us to reduce the number of physical testing by approx. 35% without affecting the TXV selection process and use objective approach to study system parameters.