Review of Operational Effectiveness, Part 6
In my last post, I evaluated the impact of the “human element” on operational effectiveness and demonstrated how different groups can control our OEE. I provided an example of the impact of 15 minutes of downtime due to late arriving materials, 20 minutes waiting for a quality inspection, and 10 minutes waiting for a relief operator to arrive on availability.
In this post, I will examine two types of equipment breakdowns and how they impact OEE. Much of what I am presenting in this series is taken from my second book,  The Ultimate Improvement Cycle – Maximizing Profits Through the Integration of Lean, Six Sigma and the Theory of Constraints.
Equipment should never break down
There is an interesting phenomenon that takes place in many companies. While most managers and operators recognize that breakdowns cause major losses in manufacturing for a variety of reasons, very few companies do much to reduce the scope of these losses.
According to  Seiichi Nakajima, author of TPM Development Program – Implementing Total Productive Maintenance, “To take this loss seriously and begin reducing it requires first of all, new thinking about breakdowns.” What is this “new thinking” that Nakajima talks about? Nakajima further explains that equipment breakdowns are often caused by human assumptions and actions. Nakajima clarifies, “Many people assume that (1) it is not the operator’s responsibility to perform inspection; (2) all equipment eventually breaks down; and (3) all breakdowns can be fixed.”
Nakajima further tells us that people concerned with equipment must replace their assumption that all equipment eventually breaks down with the belief that equipment should never break down. Nakajima believes that if this change in thinking happens, then everyone involved is more likely to accept the idea that equipment can be used in a way that actually prevents breakdowns. When people accept the view that everyone is responsible for equipment, operators will want to learn how to use their own equipment so it won’t break down. What he is saying is akin to the concept of the self-fulfilling prophesy. That is, if I believe something can happen, then it has a better chance of happening. Likewise, if I believe something cannot happen, then it probably won’t.
An ounce of TPM prevention is worth a pound of cure
There are basically two types of equipment breakdowns: function-loss breakdowns, in which all functioning equipment stops and function-reduction breakdowns, in which the equipment function deteriorates. In many companies, maintenance efforts focus on sporadic, unexpected breakdowns and significant, highly visible equipment defects. Total Productive Maintenance (TPM) addresses both function-loss and function-reduction breakdowns caused by hidden defects.
While a single, significant defect can trigger a breakdown, a combination of small hidden defects which may be completely unrelated to the breakdown (e.g., dust, abrasion, vibration, and loose bolts) is often the major cause. Eliminating breakdowns caused by these hidden defects requires a different approach from conventional maintenance thinking.
Nakajima tells us that there are five types of actions needed to uncover these hidden defects and treat them properly to prevent breakdowns:
- Maintain basic equipment conditions by properly cleaning, lubricating and bolting.
- Maintain operating conditions that must be met for equipment to operate at its full potential.
- Restore deterioration because equipment slowly deteriorates over time and breakdowns occur as fatigues develop.
- Correct design weaknesses which require changes in equipment design.
- Improve operating and maintenance skills because many breakdowns are caused by a lack of skill.
Coming in the next post
In the final installment of the Operational Effectiveness series, we will continue our exploration of factors impacting OEE and I will discuss functions that must be performed by operators and by maintenance.
Until next time.
 Bob Sproull, The Ultimate Improvement Cycle – Maximizing Profits Through the Integration of Lean, Six Sigma and the Theory of Constraints, CRC Press, Taylor & Francis Group, 2009
 Seiichi Nakajima, TPM Development Program – Implementing Total Productive Maintenance, Productivity Press, 1989
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