Product redesign for reducing manufacturing lead time

Abstract

This research critically analysed the manufacturing process of a loader bucket with grapple. Such buckets are commonly used to unload dry bulk materials such as wood chips. In order to do this as quickly as possible, these buckets transport tonnes of material each cycle, the buckets themselves have a mass of tonnes too and can be as tall as 4 metres. These buckets are built to order as one-offs or in small batches, optimized for the needs and wishes of the customer. The goal of this research was to reduce the manufacturing lead time of such a bucket from 14 days to ten days or less. The bucket design was changed to accommodate a solution to the problem, but such a change should not increase the module’s weight by more than five percent, nor reduce its functionality in other ways. Each bucket has to remain specific to each customer and their requirements. This research first analysed these requirements and available variations in the bucket design. Following this, the operations in the manufacturing process were identified and analysed with regards to their criticality in the total lead time. Each operation was evaluated regarding its impact on the overall lead time, as well as the dependence on resources available in the factory, such as machinery like a milling machine. Furthermore, the dependency of other operations was also taken into account. According to these factors, the operations with the highest impact on the lead time were identified. From this, various lead time reduction methods were proposed which reduce the impact of these critical operations on the overall manufacturing process. By parallelizing the part with which the manufacturing of the bucket starts, the lead time could be reduced to just more than ten days. To reach the ten day goal, this parallelized part also had to be manufactured more efficiently. For this, six redesigns of the part were devised which do not require machining. These were evaluated in a survey among six employees from the engineering, planning and manufacturing departments. The most promising designs could reduce the expected lead time of the part itself by two days. By combining the suggested parallelization, along with the shortened manufacturing of the mounting plate without machining, the goal of a lead time of ten days could be achieved.