To address the situation with piling work-in-progress items, I would start by setting up a Kanban board to visualize the entire workflow. This board would help me see all stages of the production process and identify where the bottleneck is occurring. By categorizing tasks into columns such as 'To Do', 'In Progress', and 'Completed', I can track the flow of work and pinpoint where delays are happening. Once the bottleneck is identified, I would analyze the root cause, whether it's due to resource constraints, process inefficiencies, or other factors. From there, I would collaborate with the team to implement solutions, such as redistributing tasks, optimizing processes, or providing additional resources to the constrained area. This approach not only helps in resolving the current bottleneck but also enhances overall process efficiency and reduces waste, aligning with lean manufacturing principles.