TPM myths & mysteries
By Cliff Williams
From a purely maintenance perspective, Total Productive Maintenance (TPM) is both a tool and an effect of Lean methods, but as companies progress on their Lean journey, they will come to a stage where...
From a purely maintenance perspective, Total Productive Maintenance (TPM) is both a tool and an effect of Lean methods, but as companies progress on their Lean journey, they will come to a stage where it will become obvious that they need to implement TPM to reap all of the benefits that Lean manufacturing brings.
The evolution of TPM started with Toyota in Japan in the 1950s when the company focussed heavily on equipment reliability and capability through comprehensive preventive maintenance (PM) programs. It continued into the 1970s when the company integrated the human element into the process. This meant the involvement of everyone, from top management through maintenance, including operators.
As the goal of Lean is to provide customers with the quantity that they want, with the quality they demand, when they want it, so the goal of TPM is zero downtime, zero machine-related defects and zero machine-related speed restrictions.
The usual measure for determining improvements through TPM is Overall Equipment Effectiveness (OEE), which is: Availability % x Quality Conformance % x Design Speed %. As you can see, each of the TPM goals contributes directly to this measure.
While it would be nice to measure the whole plant, it is much more practical to start with individual pieces of equipment. These pieces of equipment should be prioritized by their criticality within the plant, or be selected if previous analysis has shown them to be bottlenecks or problem areas.
Relating any productivity gains to be achieved in financial terms will help develop support and investment in TPM from your company.
Many times when TPM is mentioned, people think of it as ‘operator maintenance’ and only that. However, while operator maintenance is a very important part of TPM, it is certainly not the whole of it. Other groups that have to be involved in TPM include operations management, purchasing, design, project management, senior management and of course the people most heavily impacted — the maintenance group.
The first step taken by some companies is in fact operator maintenance, where they give the operators a basic care checklist and set them free. This is a sure way of setting back the TPM initiative, sometimes beyond recovery.
The correct first step along the TPM path has to be consultation, especially with the two groups that will be most affected — the operators and the maintainers.
One of the supporting goals of TPM is to develop ownership and this should be communicated to the operators so that they will understand that they have an important part to play in the process.
As far as maintenance is concerned, the challenge may be greater, as these employees believe that their skills and training dictate that they should be the only ones carrying out PMs.
To overcome this mindset and enlist the maintenance group in helping to train the operators, it needs to be stated that TPM does not mean a reduction in maintenance activities by the maintenance group. TPM should be presented as the opportunity to be involved in more technical aspects of maintenance, such as predictive maintenance techniques and increasing equipment reliability.
As equipment and technologies have progressed, so have the tools and maintenance practices right along with them. Today’s handheld data logger has the storage and computing power of the first mainframe computers. Accelerometers and vibration pens can give a much better indication of equipment health than listening to the trusty old screwdriver (although there may be some experienced tradesmen who will argue otherwise).
The result of this re-directed maintenance should be extended equipment life cycles or, if measured, an increase in Mean Time Between Failures (MTBF). An added benefit for those organizations carrying out detailed Root Cause Analysis is better data and the involvement of those closest to the failure — the operators.
One of the precursors to implementing TPM is the implementation of the 5Ss (see Machinery & Equipment MRO, Nov. 2004, pg. 41). This involves the operator in the cleaning of the machine. The operator will need to be trained and qualified in how and what to inspect for, how to make correct adjustments (for example, just tightening gland packing nuts without knowing the implications is not advisable) and the correct method and amount of lubrication to be carried out.
Some surveys have shown that 70% of failures or breakdowns are caused by improper lubrication or contamination, so the gains to be made for very little investment are tremendous.
Another advantage of operator involvement and cleaning is the early detection of problems — operators have always been able to tell when equipment ‘sounds funny,’ but in TPM environments, they will be able to hone in on the cause and either rectify it or alert maintenance to the problem.
Similarly, having operator involvement will bring to light previously hidden functional failures a lot more quickly, as typically they are first seen through process variation.
It goes without saying that the operators will receive training that was traditionally the domain of maintenance, especially with regard to safety. They will be made aware of the issues that maintenance faces daily when working on equipment and will have to be trained and competent in lockout/tagout procedures, including looking for hidden or potential energy sources, not just the obvious electrical/pneumatic/hydraulic sources.
The freeing up of the maintenance workers’ time will allow maintenance to be carried out at a component level. Along with this, a complete life cycle program can be developed to take into consideration the aging of the assets.
Before a life cycle program can be developed or even before a TPM program is developed, a current-state analysis should be carried out. This should determine the current state of your equipment, maintenance program, the complexity of your equipment, the skills and knowledge of your workforce, and importantly, the culture within the organization and each department. This information will help you determine the best path to TPM.
As we stated in a previous article, Hello Muda (see Machinery & Equipment MRO, June 2004, pg. 38), the elimination of waste in maintenance is a tool in Lean environments. It will become obvious that TPM is a natural tool for this waste elimination, as you are putting people closer to the problems and involving more of them in the solutions.
The ultimate goal of TPM is maintenance prevention and this will only be achieved when TPM has progressed to the stage where maintainers and operators are not just involved in maintaining but also in purchasing — and more importantly, in helping design the equipment. With this involvement, companies should be able to manufacture equipment that requires less maintenance and has ease of maintenance as a design feature.
As companies successfully implement TPM, they see that capital expenditures, expansions and new pieces of equipment are not necessary as they are able to produce more with their existing equipment. A pleasant side effect of successful TPM is the resultant happier workforce, with better relationships between departments and fewer frustrations.
TPM is not a program to be entered into lightly, as it is not just a ‘flavour of the month’ project, but a long-term program. Return on investment (ROI) is seldom seen in the first year, but the rewards of the subsequent years quickly overshadow this.
It is a program that requires the commitment of the whole organization to training, involvement, resources and most often change. If you are starting out on the TPM journey, keep focussed and good luck!
Cliff Williams is engineering and maintenance manager at Multipak Ltd., Mississauga, Ont., and a consultant with TMS Total Maintenance Solutions of Markham, Ont. He can be reached at firstname.lastname@example.org. To review his p
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