The expansion of economic growth in Bangladesh results in making the leather industry an emerging foreign exchange earner. Although the supply of raw skin is high and the availability of labor is cheap, the industry is not showing it’s full capacity within which it can perform. It happens due to non-structured and less productivity based production system. This study will observe the problem by focusing on a tannery which is situated in BSCIC in Savar that works with Wet-Blue Leather. The general objective of this study is to develop a continuous quality improvement model and combine Lean and Six Sigma concepts to reduce defects and increase the sigma level. The study is comprised of primary and scondary data by using Snowball sampling. The primary data includes, process mapping, defect types, cause and effects, as well as secondary data includes, firm records, defect prevalence and lead times. It constructs DMAIC structure (Define, Measure, Analyze, Improve, Control) with Lean tools such as, SIPOC, Value Stream Mapping, Pareto analysis, Ishikawa diagram and Control Charts. The finding shows that the causes of defects are mainly shortage of manpower, equipment, raw material, improper technique and process, lack of organizational practices. Therefore, the implementation of the systematic and continuous improvement framework raised sigma level from 1.82 to 1.98 and also proposed a future Value Stream Mapping. Although the improvement isn’t large enough, it will pave the way to create a great practice in the tannery industry.