TBB one of the biggest stores in PT BHJ or PT SBP which is a supplier of accessories products in Indonesia. Products at TBB are finished and semifinished goods that areimported in large quantities, so they require more space. TBB has various types and sizes of products that are stored in limited warehouses. The buying and selling process often experiences problems when searching for products, one of the reasons is the WMS that has not been running well. The first step in improving WMS is to find the root of the problem usinga Fishbone diagram and then analyzing it using 5W1H. the results of the study stated that there was no Jobdesk and workSOPs because there was no special leader for warehouse operations which causes WMS not to run.