Quality is an important factor in production, so companies must maintain the quality of their products in order to be able to compete in the market. One of them is PT. Swadaya Graha operates in the construction and fabrication services sector, working on several projects, one of which is pipe support. In pipe support fabrication there are problems during the production process. This problem is the presence of "scratch" defects on the surface of the material. The aim of the observations carried out is to minimize the occurrence of production process defects in pipe support fabrication. From the results of the analysis using a cause-and-effect diagram, there are 3 factors that cause defects. And improvement efforts to minimize defects using the 5W + 1H method.
 
Keywords: Cause-Effect Diagram, Defects, Scratch, 5W + 1H Method.