Hieu brings 25 years of QA experience. He works with engineers and other personnel regarding product information such as design, capacity, purpose, and types of materials for fabrication. Hieu analyzes written specifications, drawings, rough sketches, and oral instructions to plan layout and determine the sequence of operations. Plans machining by studying work orders, blueprints, engineering plans, materials, specifications, drawings, reference planes, locations of surfaces, and machining parameters; interpreting geometric dimensions and tolerances.

In addition, Hieu tests experimental models under simulated operating conditions for development, standardization, and design feasibility. He also evaluates experimental procedures and recommends changes or modifications for efficiency and adaptability to setup and production. Hieu reviews, considers and makes recommendations for purchases such as supplies, materials, and/or equipment. Also supervises employees engaged in production support activities, including requests for hiring, termination, performance evaluation, training, work allocation, and problem resolution.