In any manufacturing business, product quality is vital to producing products that meet the reliability standards that customers require. Line efficiency is equally important such that the quality products demanded are produced in a cost effective manner for the seller and offered to the buyer such that the price value is recognized. Process improvements are constantly sought, however, when a new customer specification cannot be achieved, line deficiencies must be identified and corrected. The revised standards must then be established and implemented in an organized and time sensitive manner. Ducommun LaBarge Technologies (DLT), an electronics manufacturing services (EMS) provider, was required to pass an SIR test as part of a new customer specification. Initial tests utilizing their current processes were not successful due to the presence of flux residues. This was attributed to deficiencies in the cleaning process. Thus began the analysis of their SMT procedures with particular emphasis on the cleaning process that was utilizing an aqueous cleaning agent and a spray-in-air inline cleaner. A design of experiment (DOE) was developed employing IPC-B-36 and IPCB-52 test coupons. Numerous process variables were reviewed and adjusted in a sequential manner throughout the DOE process. This included cleaning agent characteristics, such as concentration, and the inline cleaner set-up including spray bar number, nozzle type and configuration, spray bar pressure, wash and rinse temperature, and belt speed. Cleaning agent bath quality was also monitored. Through all steps of the DOE, improvement progress was validated initially through visual inspection and finally through the successful passing of the required SIR testing. This study maps the process optimization plan pursued in order to successfully meet the product quality specifications required by DLT’s new customer.