Lean Manufacturing Requires Responsive and Reliable Maintenance

Lean operations require maintenance that is responsive and reliable.  When we have isolated operations that are adding value to pieces in a batch that eventually gets passed on to another operation, one machine going down does not present itself as a critical event.

If we have many operations organized in a cell and one piece of equipment breaks down, the entire cell goes down.  We require equipment that does not go down very often – ideally not at all – and when it does go down we need to get it up and running as quickly as possible.  This imposes requirements on the maintenance system. The maintenance system is not limited to the maintenance function.  The system includes standard procedures that are followed by the operators and equipment that does not breakdown and/or can be repaired quickly.

A good way to begin to improve the maintenance system starts with a workshop focused on a single piece of equipment that is or will be critical to a lean, one-piece-at-a-time operation.  The workshop team goes through a process of detailing the machine.

Standard Procedures Do Not Have To Be Regimented

Sometimes standardization smacks of regimentation. Workers say, “We each have our favorite way of doing things.”  Implicit in this is, We like it the way it is.  Don’t try to shoehorn us into a one-size-fits-all mold.

Standard work is essential to mass production, even to fairly small-scale mass production.  It is at the core of a quality process that provides a quality product.   A defect is essentially something that deviates from what it should be. The best way to get consistent results is by having a consistent--that is standardized--process.

Standardized work can be regimented, but in the best cases it is organic.  Standards are developed based on our experience of what needs to be controlled in the process.  The standards are implemented.  Their effectiveness is studied and adjustments are made to improve them.  New standards emerge on the basis of our experience of what needs to be controlled in the process.

Leadership in the Workplace

I have mentioned that leadership places a crucial role in bringing out the best in people and the organization at the workplace.  We will explore the nature and role of leadership.

I have explored leadership with clients by contrasting it to management.  Management focuses on maintaining the states quo. This is important.  Organizations need to have consistency.  There need to be standard procedures.  Value-adding processes cannot accomplish their purpose without support around people, machines, methods, materials and measurement. These support systems need to be managed.

Leadership is focused on change.  If we want to move the organization to a new way of operating that is lean, world class, and brings out the best in people and systems, we often need to change the way we do things.  Many of my posts so far have been about things that need to change and how they need to be changed.

What Else Gets in the Way?

Sometimes managers who are very enthusiastic about their kaizen experiences can be the obstacle to improvement in the kaizen way. At one factory the plant manager was one of the most enthusiastic people whom I had ever met.  After a couple of successful workshops with gratifying results he was ready to have “a kaizen event a week.”

This became a problem for one of the reasons I have already mentioned. The support systems for the new, lean, one-piece-flow, work to takt time approach were not in place.  The maintenance system could not respond when equipment went down.  There was not a system of supplying materials in small amounts.  Water-spiders from the early workshops would get drafted to do production work to cover for absenteeism.  Many of the products were fairly low volume, but suppliers brought in huge amounts of components.

Read the Small Print

 This is from gemba panta rei.  You want to become lean?  Better read the fine print:

So here again is my offer:
Lean Brings You Fast Results! Recognition, Pride and Prosperity Can All Be Yours with Lean! Try Lean Management Today!
May require significant changes to leadership behavior. May require dismantling existing reporting structures, organizational boundaries or performance measurement schemes. Positive results due to employee empowerment may be accompanied sense of grief due to perceived loss of power, position or authority. May cause adverse interactions with existing accounting systems, ERP systems and vendor management systems. Results may be delayed due to resistance from key stakeholders. Side effects may not be reversible even if lean management is abandoned. Seeing bottom line results may depend on business growth or restructuring. Actual results may vary. Sustaining of results may require constant effort. Not applicable in industries and processes where waste does not exist. One per customer. Some restrictions apply. Offer void where prohibited by law.

Quality Process and Quality Results

How do we assure that our customers receive the highest possible quality in our products?  The first thing that comes to many people’s minds is that we need to have plenty of inspection.  Defective products will get made and we need to catch them before they get to the customer.

Unfortunately, inspection (as well as various kinds of testing) does not catch every defect. No inspection process catches every defect.  Many let 20%, 30% and more escape.  Inspections can also catch products that turn out not to be defective.

In workshops, we demonstrate the unreliability of inspection by having each participant independently count the number of a certain letter (for example, “e”) that can be found in a text. All counters do not come up with the same number. If the letter were a defect, some would not be caught in the inspection process.

Inspection does not add value.  It only catches some of the defective products and leads us to other work that does not add value either, but does add cost.

Takt Time

One of the concepts used by companies that are moving toward leaner operations is takt time.  It is also a concept that is often misunderstood in companies that have had a little exposure to lean processes and have picked up the term.

Takt time is the beat at which we should make a product or component to be in synch with the needs of the customer. The customer may be an internal customer such as a downstream process, or it may be an external customer, a dealer or an end user. Takt is a German word for beat when the subject is music.  The baton used by a band or orchestra leader is called a taktstock.

Let us suppose that a customer of any type needs 900 units, widgets of some kind.  The factory works an 8-hour shift, but a half hour a day goes into breaks and other planned downtime, leaving 7.5 available hours.  Seven and a half hours times 60 minutes, times 60 seconds, equals 27,000 seconds of available time in a shift.  If we divide 27,000 seconds into 900 units, we find that our takt time is 30 seconds per unit.  To be perfectly synchronized with the customers requirements for a day, we need to produce one widget every 30 seconds and each operation in the process should take exactly 30 seconds.

Treating People As If They Were Robots

I have consulted to a number of plants with recently acquired robots.  Often the robots didn’t work very well.  In some cases the robots were doing work that made little sense.  In one case, the robot was taking a stamped part from a hanging line and putting it on a belt. It was so unreliable that a worker had to stand by to catch parts that were about to be dropped by the robot. Having the hanging line descend to just above the belt could have removed each part without a robot.

In a factory in Brazil, a robot cell had been installed to weld some parts together. A second cell was in the process of being installed.  Management was very proud of it’s new technology.  They had a five minute video of the robots in the dining room.  The bright orange robotic arms waved through the air and set forth a shower of sparks with each weld. The dramatic video played endlessly, for all lunch breaks on all shifts to see. 

Not a week had gone by since the robots were installed when they didn’t break down and required repair. No one in the plant could do the repair and the technicians who could do the repair were four hours away.  When they arrived it often took an entire shift to get the robots up and running again.