Improving Productivity of a Repair Cell

Daniel Penn - Case Study

Client:  A manufacturer of tankless water heaters for commercial and residential applications.

Goal:  Increase the capacity for repairing hot water heaters by making the cell’s operations more effective and then more efficient.

Seeing the forest and the trees.Requirements: Review the hot water heater repair process and develop improvement ideas that will enable the cell to meet the company’s 2017 demand forecast. Implement those ideas that can be completed during a three-and-a-half day kaizen event. Develop an action plan to implement additional ideas.

Initial Tasks: Led by a Daniel Penn Associates senior consultant and facilitator, the repair unit’s team began by reviewing key lean and Kaizen principals that would guide the improvement event. The group then mapped the process, observed it, and measured time required for the repair cell’s current operations.

Findings: The repair cell’s receiver had to double-handle incoming parts. This activity, which should have taken less than two minutes, was taking from two hours to two weeks. The repair operators did not follow a standard approach and would make repairs as they tested specific components, not looking at the overall repairs needed. In some cases, the cost of repairing a part was more expensive than purchasing a new part.

The order of functional part testing and packing was not consecutive and logically laid out. Some repairs needed to units were missed, impeding the flow of testing. Operators walked up to two aisles away from their stations to obtain repair parts. Test stands were not located within the cell; parts were not available to repair many units.

Actions: Redundancies were eliminated: The cell’s receiver now handles parts only once when bringing them to the cell. Repair operations were divided into diagnose and repair functions. A visual tool was created to help the operator identify what repairs are needed and whether the repair costs justify the repair. Units requiring more time and effort to repair than the cost of a new unit are scrapped. To minimize travel distances, parts were moved to the racks directly behind the repair stations. Partially repaired units waiting on parts were moved out of the immediate area. Functional testing steps were re-ordered for more efficiency. Standard work instructions were created for diagnosis, repair, and functional testing. These work instructions were reviewed with operators, then tested and modified.

Based on the new standards and procedures, the team revised the cell’s layout and began labeling the Diagnose/Repair workstations. Functional testing will be moved into the cell, and a concept for new test stands is being developed. A table was added to the packing area and some packaging supplies were moved closer to their point of use.

The kaizen team and DPA facilitator met with the company’s purchasing department to review the repair parts process to date and set future action items. An action plan was created designating a responsible person and estimated completion date for all open improvement items.

Project Baseline-to-Benefits Comparison:

The repair cell team did trial runs of the new process with two hot water heater models. Repair time per unit decreased by 25 percent, from an average of 45.5 minutes per unit to 33 minutes per unit. On the day of the trials, 54 units went through the repair cell with the same level of operators. Based on the time saved and assuming a conservative 50 percent interference, the cell can now repair 237 units per week, beating the 200-unit goal with a productivity improvement of 137%.

“Since holding the Kaizen event with Daniel Penn Associates, our business is seeing immediate results. We have reduced our backlog to manageable levels and have improved flow through the cell. The manpower cost to repair units has decreased. Quality of work is up and proven by a first pass yield at testing. This event has supported our strong position of competitiveness and is helping us keep this work in Connecticut.” —  Kathy Daudish, VP of Engineering and Operations