Reliability = Zero Breakdowns

March 25, 2019

 

From a reliability perspective, think about it - zero breakdowns. It sounds radical. It was first proposed by Seiichi Nakagima in his book that introduced Total Productive Maintenance in 1981. Terry Wireman built on Nakagima’s work with a book titled Zero Breakdown Strategies. Zero breakdowns shares Total Quality Management DNA with Lean and Six Sigma. What’s unique about zero breakdowns is that it’s designed specifically for production equipment reliability.  

 

Performed on individual pieces of equipment, there are five “actions” required for zero breakdowns:

  • Maintain basic equipment conditions (cleaning, lubricating, bolt tightening).

  • Adhere to operating conditions (running speeds, operating loads, ambient temperatures).

  • Restore deterioration.

  • Correct design weakness.

  • Improve operator and maintenance skills.

The power of those five simple actions has proven their worth repeatedly. Asked to take a look at downtime on a rolling mill, we used the five actions to guide interviews. Issues quickly became apparent. The big hitter came out when discussing adherence to operating conditions. At times sales people were agreeing to provide plate in widths slightly greater than the mill’s designed capabilities. The solutions were outside of the maintenance and reliability organizations. They lay in customer service, marketing and equipment design.

 

Great successes have come using zero breakdowns to focus a cross-functional team on a single piece of equipment, charted to achieve specific, measurable objectives. The team includes operators, maintenance and engineers, all of whom work with that specific piece of equipment. Other functional groups (purchasing, human resources) are on call if the team needs input. What follows is an example of how it works.

 

Situation:

The plant produced high impact poly-amide plastics going to automotive manufacturers for molding into dashboards and interiors. The finished product looked like little ⅛ inch “pillows” of hard, opaque plastic shipped out in bags, octabins and bulk. The manufacturing process started with batch polymerization in autoclaves on the second floor. The hot, liquid polymer flowed out of the vessels through the floor into cooling and separating channels at the top of German-made Automatik cutters on the ground floor. The product, formed into spaghetti-like strands in the channels, flowed across a rotating drum with cutter blades that cut the pillows, dropping them onto conveyors to the packaging area.

 

There was one Automatik cutter for six autoclaves. The Automatik was rolled on rails under the autoclaves to align with the next autoclave ready to drop its batch.

 

The issue was the Automatik cutters producing non-uniform particles, NUPs. The pillows could have tails off the corners or be crimped. The different configurations would wreak havoc with customers’ melting and molding processes. There were times when an entire batch was plagued with NUPs, causing rejection of the entire batch.

 

We formed the NUPs team with an experienced engineer, mechanic, electrician and two operators. We scheduled a weekly four hour work session with homework, as needed, between sessions. We acted as facilitator to allow the team to focus on content. The facilitator helped the group meet meeting time contracts, stay on agendas, distribute notes and follow up on next steps.

 

The team started with Automatik orientation. Engineering went over the Automatik cutter (configuration and functionality). Quality Assurance reviewed the various types and known causes of NUPs. Line management went over why fixing NUPs was important and the history of what had been tried, what worked and what didn’t.   

We introduced the five actions to orient the team to the scope of the range they should explore. Work started with their inspection of the Automatik and listing actions to take. If anything seemed slightly off or there were any doubts, it went on the list.

 

Restore deterioration 

The lists included components to replace or repair. The team prepared for and performed several Kaizens, replacing guards, bent railings, mounting operating instructions at the operator’s position and restoring the “doughnut holes”.

 

These were steel flanged holes in the concrete floor, one hole to the North and one hole to the South of the Automatik rails, directly under each autoclave. The Automatik was moved to a ready autoclave by lifting the cutter off the floor hydraulically, rolling it on the floor rails under the ready autoclave. The doughnut holes (maintenance’s terminology) were guides for setting pins on the Automatik into the doughnut holes and lowering the cutter…a first step in aligning the cutter’s top channels with the autoclave output.

 

Improve operator and maintenance skills

Once restored, maintenance tested the doughnut holes, moving the cutter, attracting the attention of all the operators on shift. The operators, “Didn’t know what the holes were for.” They had been aligning the cutter by eye, using the Automatik’s North/South, East/West channel adjuster as the primary means to align the cutter. It turned out that three years prior there had been a massive lay off because of lack of business. Experience with moving and aligning the cutter was lost. The doughnut holes were supposed to be the first, rough alignment. The channel adjustment mechanism was supposed to be used as the final, fine alignment of the cutter under the autoclave. NUPs reduced with implementation of the doughnut hole alignment.

 

Maintain basic equipment conditions

Next the team addressed settings for rates of drum rotation and cooling water flow. They found variation between shifts. Operators would come on shift and immediately adjust the rate to their personally preferred setting. Operators had taken to jockeying rates trying to combat NUPs. The team established standard rates by product, not to be changed by operator preferences. NUPs declined again but persisted.

 

Next the team looked at maintenance of the cutter blades and rotary drum. Procedures were followed precisely replacing and sharpening blades. The vendor instructions called for replacing the rotary drum after 25 cutter blade change outs. The drums were left in place since blades had been changed out just 18 times since the last replacement.

The vendor was brought in to assess the cutter. They felt the cause must be in the materials or production of the polymers in the autoclave. The team engineer began looking at salt and feed-stock quality as well as autoclave integrity.

 

Then, the team mechanic thought to measure the diameter of the rotary drum, even though it had not reached the proscribed change outs for replacement. He found that the drum was less than a millimeter under its minimum diameter. The team ordered and installed new rotary drums.

 

NUPs stopped. Every individual on the team was ecstatic. They had worked with people in ways they never had before. As team members, their input and contribution was valued. And they were successful. Management was ecstatic about the team and the result.

 

Winning Combinations

The advantage of zero breakdowns is that it clearly directs one to examine how equipment is currently being used (versus designed capabilities) and the organizational skills sets. How often have you heard operators say that maintenance can’t fix it right and maintenance say operators abuse the equipment? Zero breakdowns objectively says check them both.

 

Cross-functional teams working together puts all the key players together to solve common problems. And, as they do that, they get to know one another in ways not previously possible. It’s a major reward when I’ve heard a team member say, “You know, I’ve known them (team member from a different function) for five years. We were usually just in each other’s face dealing with some crisis. But, now, I see they really are a great person. They just want to help.”

 

Employee engagement is gaining increased attention of corporate leadership. The expressed objective of employee engagement is improved productivity and reduced turnover. Engaging employees on structured problem solving teams is one of the most effective ways to engage employees in a very direct and real way. Engaging employees in activities that also have a measurable payoff has big wins all around.

 

 

  

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