Rework of Robotic Welding Cell Floor Plan at AGI Westfield
AGI Westfield is the largest manufacturer of grain augers in the world. To produce the frames for these augers, their Manitoba facility uses three welding cells: two manual and one robotic. The robotic welding cell was added in most recently and was designed to fit in a small space rather than having frame throughput be the more important design goal. The objective of this project was to design a customized robotic welding cell layout that had reduced downtime compared to the current cell for inclusion in a facility expansion that AGI Westfield is planning. Downtime here refers to long changeover times and a layout that causes the robots to be frequently waiting for raw material. The current robotic frame welding cell experiences changeovers that last an average of 90 minutes. This is because there is nowhere to stage the jigs and so only when a batch of frames is completely welded can the forklift remove the cart of finished product and bring in the next jig for the new size of frame to be welded. This is a lengthy process since the jig storage is located approximately 600’ away from the welding cell and requires a forklift to bring them over. This is especially problematic since forklift availability is inconsistent and also the timing for when a cart of finished product needs to be picked up via forklift is inconsistent. After screening several design concepts and using the Single Minute Exchange of Dies (SMED) concept, the design team developed a new layout that will reduce the changeover times to 15-20 minutes. This was done through the addition of an elevated staging area, a mezzanine, specifically made for jigs that sit over the primary staging area. The primary staging area located under the mezzanine is used for raw materials flowing into the cell. The jig storage was also moved closer to the point-of-use. The current robotic welding cell also has back-and-forth material flow and the raw materials and finished goods are placed in the same area. This wastes time since operators perform redundant raw material movement to create space for the finished product. To mitigate this time loss, the team also designed the entire structure of the cell to encourage the flow of materials. This meant moving individual cell elements so that material would flow in a circular path from the inlet to the outlet, eliminating the redundant material movement. The proposed cell makes extensive use of a two-point-of-contact (POC), two degree-of-freedom (DOF) hoist system to quickly and safely move materials and jigs throughout the cell. This is an upgrade from the current single POC, single DOF hoist in terms of safety due to the additional POC, and an upgrade in material movement versatility with the additional DOF. The redesigned robotic welding cell was calculated to have an increase in output of auger frames by 1,494 frames/year (16% increase) while only increasing the floor space used by 400 ft2 (11% increase). This translates to an increase in cell profitability of $977,000 each year. Additionally, the OEE was improved from 80.9% to 91.7%. These values are inflated since it excludes the quality (%) metric as it was out of the scope of the project.