Poka-Yoke

Problem StatementThe Autophoretic Coat line at Duramatic is operated using a programmed hoist. Strict specifications and timing govern how operators position WIP to have the process applied. Carts that hold racks of blades (360 pieces) are positioned against a rail where the hoist picks up the racks for movement along the line.

• This rail has been damaged and bent by years of improper use. If any carts are mis-aligned, the hoist will crash into the cart and rack spilling the lawnmower blades onto the floor. This presents a safety concern as well as excessive labor costs, re-work, and scheduling issues.

• Crashes occur twice per/week. The existing process does not require any adjustments to the wheels to prevent a crash.

• It is is a knowledge based error. Improvisation in an unfamiliar environment is occurring where no firm guidance exists. There are no routines or rules available for handling every situation

Background

• Operators are currently eye-balling the carts to a relative position and physically kicking the castor wheels to prevent the cart and rack from moving. Divots have been worn into steel deck plates from years of manual adjustments. Operators’ boots show signs of wear and tear from kicking the wheels to make them rotate 90 degrees.

• With 209 racks combined between 2 shifts, over the course of a year, this equates to 75,240 blades falling on the floor.

Although only 1.68% of the production of 4.4 million blades annually, this requires 35 hours of additional handling and rework plus an additional 35 hours is lost in production due to the line not operating.

• This equals $756 annually

• There is evidence of variation between operators on different shifts.

• RPN is 200/1000.

• Safety was the major factor in this device.

Current Situation

• Problem: Loaded racks fall over and spill sharpened blades.

• Why #1 Flight bar is struck by hoist.

• Why #2 Racks are not seated correctly in jig.

• Why #3 Jig is bent and divots are in the floor.

• Why #4 Operators have been kicking the wheels, and making them rotate 90 degrees.

• Why #5 To prevent the racks from rolling out when contacted by the moving hoist.

Root Cause

Idea Description $ Cost S F D RPN E C I SPN

1 Enforce standard work instructions $0 10 4 7 280 10 1 1 10

2 Modify the damaged jig $300 10 2 6 120 9 3 3 81

3 Fabricate a locking mechanism $150 1 1 10 10 10 2 2 40

4 Standardize the racks $2500 10 5 1 50 3 9 7 81

5 Standardize the carts $5000 10 5 1 50 3 9 7 81

6 Weld the wheels in the desired position $100 10 3 2 60 4 5 5 100

7 Extend the hoist beam $10,000 2 3 10 60 1 10 10 100

Target Condition (Desired State)

Action Responsibility Deadline Cost

Fabricate new jig Randy @ DBI 1/4/15 $300.00

Design & Fab. a locking mechanism Robert and Ric 2/10/15 $0

Install the locking mech. Robert and Ric 2/10/15 $0

Update work instructions Ric 2/20/15 $0

Implementation Plan

• Adherence to updated work instructions will be spot checked on all shifts.

•  All metal surfaces of the new device will be monitored for surface rust and painted as necessary.

Follow Up Plan