Viewpoint: planning for downtime
29 May 2016
In advance of scheduled downtime, plants have to ensure maintenance activities have been fully resourced, carefully planned and efficiently executed, says Brammer’s Terry Davis.
Gone are the days of the traditional two-week summer shutdown – today’s manufacturers have to fit maintenance around production demands, which means shorter windows, longer intervals, and often less notice.
As one of the most resource-intensive activities a manufacturing facility can undertake, all aspects of a shutdown or planned maintenance must be justified. In the past, when putting together a work plan, certain activities such as oil changes were scheduled simply because it was always done during such a period, rather than because of a specific need.
Now high performance condition monitoring is playing a role in ensuring that old practices are challenged to uncover true best practice.
To continue the example of a hydraulic oil change, many facilities prescribe a change every six months where the oil may actually last a year or more.
Many activities scheduled for planned downtime will be uncovered as a result of such condition monitoring, analysis of mean time to failure, and known equipment life cycles
Frequent condition monitoring and oil sampling will reveal the correct interval for changes, which in many cases means the oil is left in situ for longer, reducing the cost of disposal and new fluid.
Many activities scheduled for planned downtime will be uncovered as a result of such condition monitoring, analysis of mean time to failure, and known equipment life cycles.
Alongside the condition monitoring achieved through remote data systems, the role of the equipment’s operator in the process shouldn’t be overlooked either.
Coming to know their machinery as well as they know their car, they can flag changes of pitch, deviations from normal operation, increased heat and other factors which may be symptomatic of damage.
Operators should always be engaged when planning for downtime, and plants that encourage everyone to take responsibility for maintenance will be well ahead in this respect.
After using condition monitoring, visual inspection and root cause analysis to develop an outline plan, maintenance teams need to ensure they have all the tools to complete each activity by referring to the spares list provided by the original equipment manufacturer (OEM).
Tight schedule
For example, some equipment such as filter-regulator-lubricators (FRLs) may be installed at height or behind other machinery. Scaffolding may be required to assist with access, and its installation needs to be factored in to the overall timetable.
The aim of planned downtime is to return the equipment to the same or better state as it was beforehand. Therefore, even if equipment has been inspected prior to downtime and all condition monitoring data is analysed, time must still be allocated to manual inspection as damage and other issues will no doubt be identified and added to the schedule.
As well as giving the opportunity to inspect related components in more detail, time must also be allowed for testing and monitoring devices to be fitted to improve predictive maintenance in the future.
For example, real-time lubrication particle detectors can provide crucial data on the health of hydraulic oil, which can both prevent unnecessary oil changes as well as flagging any deviation to assist in early diagnosis of contamination.
Other manufacturers may use the occasion to fit flow meters to compressed air lines to monitor pressure and identify opportunities for point-of-use pressure and flow reductions, thus saving money.
Time must also be allowed for testing and monitoring devices to be fitted to improve predictive maintenance in the future
Before planned downtime, engineers should assemble a kit of all possible components required, with the help of specialist maintenance, repair and operations (MRO) distributors that allow manufacturers to return unused items afterwards, only paying for what has been used.
When selecting an MRO partner, this flexibility must also be matched in their ability to meet demanding schedules because planned shutdown doesn’t always happen 9 to 5, and distributors and technical support teams must be able to work around this.
- Terry Davis is national technical manager of Brammer.
