During a July 2018 visit, the corporate EHS team, along with EPC leadership and an OT Champion, identified material handling on one of our presses as an area for ergonomic improvements. A kaizen was conducted resulting in a rapid experiment that tested the use of a conveyor to supply parts to the operator on the raised platform and eliminate lifting heavy boxes. Following the kaizen, a spaghetti diagram was created of the operator’s motions on the platform, and a rough improved cell layout idea was sketched.
With the commissioning of a second identical vertical press a few weeks out, our Director of Engineering, Manufacturing Technology Manager, and Manufacturing Manager decided that all of the parts that need additional components and subassembly would be routed towards the press being observed. Future improvement efforts were then concentrated on this press and any transferrable improvements were carried over to our new press.
Operators lifted 30 lb. boxes of raw materials and stacked them up on the platform. They were then lifted again to transfer the parts to a bin at the point of use, adding up to a total lifting of 5ft. from the floor.
The first attempt at improving ergonomics was made by creating gravity flow racks, which presented the boxes at a comfortable height for the operator on the platform. Boxes would be refilled by anyone passing by the press, one box at a time. The flow rack worked great for the smaller insert boxes, however, in the case of the discs, it was realized that operators went through more boxes per shift than what the flow racks could hold. Refill frequency couldn’t match up to the production rate.
Cardboard Engineered Conveyor
Taking a cue from the rapid experiment carried out by the kaizen team, an existing conveyor was cardboard engineered to get the discs directly from the floor to their point of use on the platform. The trial run was successful and received a positive response from the operators.
Root Cause Analysis for Stuck Parts
A hopper, with the capacity to hold up to 3 hours’ worth of discs, was designed, fabricated and attached to the conveyor. This design had flaws and parts repeatedly got stuck when transitioning from the hopper to the belt. After a root cause analysis of the problem, our Maintenance Technician suggested that making the hopper into one smooth continuous surface, without any sharp corners or edges, would avoid parts from choking. This new design worked better, and the parts flowed smoothly. It was easy to refill for anyone passing by with a lifting height of only 29″ and parts were presented to the operator directly at their point of use.
Feedback and Improvement Ideas
These improvements were made possible with the feedback and continuous improvement ideas provided by our BU Leads and Operators from all shifts. Thank you to our Shift Supervisors for their ideas on improving the refilling, and to our Maintenance Technician for modifying the platforms and improving the stair access.