Applying Total Productive Maintenance to Solve Machine Stoppages and Boost Output

Applying Total Productive Maintenance

Company
A global precision molding manufacturer of specialty packaging for fragrance, lotion, fine mist and foam dispensers.

The Challenge
One key subassembly machine was performing at less than 50% OEE. Six employees, representing Production, Maintenance, and Quality, formed a team to improve that performance with a target of +15%. Their initial charter was to use Total Productive Maintenance (TPM) and Single Minute Exchange of Dies (SMED) techniques to achieve this goal. The objective: seek opportunities to reduce machine stoppages and debugging issues.

 

Group of workers that applied TPM

After receiving initial training on lean and Kaizen best practices, the employee team worked with DPA senior consultant Mike Beauregard to observe and define the current process, develop improvement ideas, begin implementing improvements and create an action plan.

Eiminating the 8 Wastes

Observing the Current State
The team spent time on the production floor examining the machine and discussing the process with other operators, the lead mechanic, maintenance and engineering. They brought in the line’s second shift for their input and reviewed downtime data.

Causes of Stoppages

The team quickly realized that changeover time for the machine (less than 5 minutes) was not an issue, so they began digging into root causes of the stoppages. They discovered that parts frequently became jammed in the retainer and piston tracks. When jams occurred, the machine shut down automatically to avoid damaging it and to stop production of compromised subassemblies. The team observed that tracks were not regularly cleaned, which led to the misfeeds, and that some well-intentioned equipment modifications were hurting the operation.

Prioritizing Solutions
To help the machine’s operators reduce stoppages and avoid debugging the machine after it jammed, the team brainstormed 46 improvement ideas and worked on 33 of them.

Idea Responsibility Status Note
Tracks General

Polish tracks on a regular basis

Jason

We polished the Piston track. Set as part of the PM (every 600 hours of operation).
Teflon spray on tracks

Drop. Can’t use Teflon spray. Should tracks be made out of Teflon?
Sensor to turn off air if track is full

To prevent air from knocking parts off. 216 has this now. Table for now.
Kick off jammed parts at stoppage points

Too much engineering for right now.
Tops of tracks have too many bolts. Convert to hinged tops with clamps.

At minimum take some of the bolts out of use. Try fewer bolts for now. Drop – Jason indicated that they are needed to seal the air in.
Set the top of the track spacing with gage blocks to ensure repeatability.

Better to go with next item. Drop.
Change design of tracks to have fixed gap for tops.

Set based on tolerance of parts. Future consideration.

They developed and refined the track cleaning procedure and created a visual guide to help the operators remove poor quality parts before they entered the line. They polished the retainer track, then realigned the piston and stem tracks and cleaned the bowls.

To minimize tweaking of the process, they developed visual controls of the set points for the vibratory bowls and airflows. They labeled each of the machine’s gauges. Through analysis, they found that removing the piston feed cover, which had been added after the machine’s installation, led to better parts feeding.

TPM Plan

The team then reviewed and modified the machine’s TPM plan and added track cleaning intervals (operators), track polishing intervals (mechanic), and verification of each track’s alignment (mechanic).

Fast, Dramatic Results
Changes made to the machine’s process and TPM protocols that were created during the Kaizen event resulted in immediate performance improvements.

On Day 3 of the event, the team ran post-improvement trials on the machine to determine improvements in part feed and reductions in jamming.

Effectiveness

In less than a week, the line’s employees successfully improved overall equipment effectiveness (OEE) from 49.2% to 63.4%. Once the machine’s retainer and stem tracks were cleaned, polished and realigned, OEE jumped above 70%. Based on data collected by the team, once all items in the action plan have been completed, the machine’s performance should consistently exceed the kaizen event’s 15% improvement target.

Questions or comments? Write us at info@danielpenn.com or call 860-232-8577.