You're only strong as your weakest link. While trite, the phrase embodies what manufacturing plants and processing facilities have worked for years to overcome: How do you plan for and prevent broken equipment in your lean machine?
Another trite phrase has the answer: The weakest link in a chain is the strongest because it can break it.
Preventative and routine maintenance models help alleviate downtime and boost overall production. The most popular method is Total Productive Maintenance (TPM).
TPM brings maintenance into focus as a vital part of business. Maintenance downtime is included in manufacturing scheduling, and in many cases, becomes an integral part of the manufacturing process. TPM assigns the responsibility for preventative and routine maintenance to the same people who operate that individual equipment. This puts the people most familiar with the machine in charge of its care.
TPM is built on the 5S foundation, which creates effective workplace organization and standardized procedures to improve safety, quality, productivity and employee attitudes.
In the most basic sense, the three goals of TPM are zero unplanned failures (no small stops or slow running), zero product defects and zero accidents
The Eight Pillars Of TPM
As with the entire body of lean manufacturing systems, TPM originated in Japan. An organization called the Japan Institute of Plant Maintenance (JIPM) formed in 1961 under a different moniker and unveiled the TPM concept a decade later.
The Japanese automotive supplier Nippondenso is credited with first utilizing the process, and Seiichi Nakajima of JIPM established eight management pillars, for which TMP is well-known today.
TPM aims to increase productivity, efficiency and safety by empowering operators and team leaders to play a proactive role in day-to-day lubrication, inspection and cleaning. Management is tasked with creating a “buy-in culture” to support continuous activities through eight pillars of activity.
- Autonomous Maintenance: Operators monitor the condition of their own equipment and work areas.
- Process And Machine Improvement: Team leaders collect information from operators and work areas, then prioritize preventative maintenance and improvements.
- Preventative Maintenance: Operators and team leaders share preventative maintenance tasks and schedules.
- Early Management Of New Equipment: Team leaders anticipate and plan for parts of equipment lifecycles and report to mangers based on maintenance reports.
- Process Quality Management: Shared responsibility for operation and maintenance encourages quality improvement ideas from all areas of work.
- Administrative Work: Managers prioritize data from the previous pillars and share outcomes with team leaders and work areas.
- Education And Training: Continuous improvement includes operator and work area education and training which improves morale, retention and efficiency.
- Safety And Sustained Success: Facility-wide safety is prioritized, which positively impacts sustained success of the TPM program.
As maintenance is traditionally considered an inevitable and “not-for-profit” function, TPM is considered the most difficult lean manufacturing tool to implement. Shifting cultural beliefs within a facility, from the CEO to machinists and janitors, may take years, but the payoff for both the finished product and employee morale is worth the investment.
Japan Institute of Plant Maintenance
JIMP still operates today as both a survey and research facility testing TPM technologies. The organization is currently researching equipment life cycles and state-of-the-art maintenance technology and repair.
According to JIMP, there are two types of aging of equipment life:
- Aging of equipment itself: The product life of the equipment itself comes to an end through aging of parts, fatigue in spindles and foundation, paint deterioration of buildings, towers and vessels and increase in discontinued products.
- Aging of functions independent from aging of the equipment: The product life of the equipment itself has not ended but suffers incapacity or inability to meet required quality, stricter requirements on quality and obsolescence with products in the market.
Companies have taken advanced approaches to predicting when a machine will break down. Two metrics used are Overall Equipment Effectiveness (OEE) and Total Effective Equipment Performance (TEEP).
- OEE quantifies how well a manufacturing unit performs relative to its designed capacity, during the periods when it is scheduled to run.
- TEEP measures OEE against calendar hours.
While state-of-the-art technologies for equipment life prediction are advanced, JIMP claims it's difficult to predict the month-by-month deterioration of machinery that has been used for 30 years.
The organization is currently utilizing equipment diagnostic technology and the data analysis system, to provide maintenance best practices in assembly processing, automotive, semiconductor and food industries.