National Dual Training System (NDTS) implementation in Malaysia was designed to produce highly skilled and knowledgeable K-workers, equipped with the social skills and learning methodologies. Research used documentation as data collection methods and data was analysed using historical, inductive and deductive reasoning method. The Ninth Malaysia Plan has stated four challenges which need to be addressed in developing the Technical and Vocational Education Training (TVET) sector. One of the issues is competency gaps among instructors. Based on the issue, the research objective is to identify the competency levels among instructors of NDTS. There are three aspects need to be applied by instructors during their teaching and learning session which include (1) technical skills, (2) knowledge, and (3) behaviour. This research is further into assessment as the platform to measure competency quality among the instructors of NDTS. The result showed that, the assessment based competency is able to improve the competency levels among the instructors of NDTS.