Overall equipment effectiveness (OEE). Total productive maintenance (TPM). Reliability Centered Maintenance (RCM). The guidelines are not new. But for companies that truly want to maximize their equipment uptime, productivity and quality, a disciplined approach is critical. So is creating a culture where everyone understands and carries out their role in the maintenance continuum.
Asset utilization, also called Overall Equipment Effectiveness (OEE) or equipment capacity, is not just the responsibility of one department. It is the responsibility of the entire company. It has the focus of ensuring that nowhere in the world does another company have the same assets or produces greater capacity from those assets. It means being the best at getting the most out of the assets by measuring and managing availability, performance efficiency, and quality rate, according to Terry Wireman’s book Zero Breakdown Strategies.
However, the wagon wasn’t maintained, so when mechanics went on a call, components hadn’t been restocked. Tooling was missing. Chemical supplies dropped to low levels or were completely exhausted. Because the maintenance store was disorganized, restocking the wagon took longer. Frustrated, the maintenance team took matters into their own hands, dedicating one wagon to unplanned machine stoppages and another to planned maintenance efforts.
A chemical processing facility had more motors in their maintenance stock room than the plant had in service. More than half of the motors and several electronic control components in stock were for equipment the company no longer owned. And because the right spares for current equipment were not on hand, unscheduled downtime stretched into weeks.
Certainly, maintenance priorities in a heavy machining plant will be different from an assembly plant or a chemical processing plant. Regardless, these practices can be applied across most production facilities:
- Borrow from successful Lean production techniques and process map your maintenance workflow. It’s recommended to begin the mapping effort at the very beginning of the maintenance process and the flow of the process from one step to the next. Once the map is done, eliminate as many of these extra maintenance steps as possible.
- When the facility is organized, it’s easier to see areas for improvement. Depending on the facility, industry and specific needs, the use of 5S techniques can be an important tool to identify problems in the maintenance process.
- Depending on the industry and facility needs, consider Single Minute Exchange of Dies (SMED) strategies to reduce machine changeover times, reduce labor and meet just-in-time production goals.
- Give machine operators process ownership. A number of real-time digital condition monitoring and reporting systems now support the positive trend to operator-driven reliability (ODR). The Total Productive Maintenance (TPM) approach shifts basic maintenance work (and problem notification) to machine operators, freeing up maintenance personnel to work on planned maintenance. The idea is to give workers ownership of their machine and the process, maximize equipment effectiveness, increase employees’ skills and reduce manufacturing costs through continuous monitoring. For their part, the maintenance team should respond to requests within a pre-determined time window.
- Schedule your facility’s planned maintenance program far in advance, just as any other operation, to maximize productivity and meet order deadlines. Annual checks are going to be more comprehensive than a monthly or quarterly check, meaning the machine will be down for longer, so make sure they synch with your production commitments.
- Use your ERP system to plan for downtime, just as it does for jobs. The ERP ties in with the procurement function, and if properly described with consumption amounts and order lead times, maintenance parts will have been ordered in advance and arrive at your plant in time for the machine to be serviced. Use your ERP or CMMS system to specify the maintenance mechanic who will work on the machine, and to specify the parts and chemicals needed to complete the maintenance activity.
- Schedule more frequent checks for older equipment. As equipment ages, parts and components will start to wear out sooner, and the maintenance window narrows. What were annual checks when the equipment was new may move to semi-annual or even monthly. The service parts required will have to be ordered more often. However, the planned downtime will affect production schedules less than a breakdown.
- Engineer machine improvements for maintainability and operability. Windows cut into guarding to give easier viewing of gauges will make the daily checks easier to perform and more likely to be completed. Access doors installed on equipment will allow for easier periodic maintenance. Consolidation of lubrication points into a single manifold also contributes to more consistently performed maintenance.
- Conduct daily operator walk-arounds to pinpoint issues and opportunities for improvement. Whether it’s a check sheet, whiteboard, or in some cases, a bar-coded activity, the operator’s checks are the essential element of a TPM-oriented operation.
- Address operator alerts immediately. Beyond the operator and the proper performance of the checks, the maintenance organization must be ready to respond immediately to an abnormality that’s been raised as part of the operator checks. Nothing will take the energy of TPM efforts faster than operators raising issues that aren’t addressed immediately.
- Continually review spare part requirements. Remove any spare parts from stock as equipment and machines are retired.
- Document and continually re-visit your operation’s maintenance history, including how critical items have been addressed. Develop and regularly review metrics that correlate equipment up and down time with production volume, quality and delivery.
Whether using a computer-based maintenance system, or relying on a card file, or having a white board in the maintenance area, the strategies, opportunities and approaches remain the same.
Once implemented, the entire workforce – from senior management all the way down to the last mechanic hired, must adhere to the basic tenet: minimize unplanned downtime through proper preventive maintenance.
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