The study's main objective was to improve the service level of a distribution and marketing company, surpassing the 93.19% indicator recorded in 2021 and reaching a service level higher than 95%. The improvement proposal focused on the warehouse's veterinary product line, representing the most significant number of income and sales of the distributor (31.63% of the monthly invoicing and a large part of the bills and invoices). Lean Warehousing, inventory management, and Systematic LayoutPlanning (SLP) methodologies were applied, resulting in a more efficient warehouse system. As a result, the monthly average time of the dispatch process decreased from 574.26 to 429.12 minutes, the daily cases of damaged or broken merchandise were reduced by 75%, and there was an incremental improvement in the cases of expired or soon-to-expire products. In addition, merchandise control improved from 87% to 98.64%, according to the ERI, and there was a 62.63% decrease in costs for total and partial returns, compared to annual losses of S/1,569,859.28 before the improvement. While applying the methodologies, it was found that implementation takes time and requires adequate personnel training.