Industries operate in a changing environment where external factors, such as market trends, economic fluctuations, government regulations and new technologies, directly impact operations, efficiency and productivity. For example, changes in demand affect resource utilization and inventory costs, which overloads or underutilizes production capacity, hurting sales and customer satisfaction. To face these challenges, industries apply strategies such as demand forecasting, production flexibility, inventory management and lean manufacturing approaches; however, no specific methodology addresses the direct effects of these external factors on production processes. This article reports on a case study applied to a manufacturing company facing fluctuations in demand in a sealing process, which exceeded the capacity of the production line and the agreed delivery times were not met. The objective of the study was to reduce the delivery time and maintain quality standards, so lean manufacturing and line balancing tools were used for a better adaptation to the demand and a 2^k design of experiments was applied to preserve quality, analyzing the variables that integrate the factors hold time preset (in its levels 1s and 7s) and post cooling preset time (in its levels 1s and 4s). The results indicate that it is possible to reduce the cycle time of the bottleneck station and keep the sealing quality at an optimum level, which allows us to reduce the total time of the station from 43 seconds to 25 seconds, thus allowing us to meet the delivery times and met the quality standards.