It’s no secret to hydraulic system engineers that implementing proactive maintenance takes both time and money. It’s for this reason that it’s important to get a grip on whether the tasks involved are worthwhile in terms of return on investment as part of the ongoing engineer’s challenge of increasing reliability. Here at Hydraproducts we have debated this subject matter at great length and we have settled on using the Reliably-centred Maintenance (RCM) approach with a set of questions to understand more with regards to our maintenance investment decision making. The questions are: · Is the machine acceptably reliable? · How critical is it that the machine is operating fully? · Will improving the maintenance of the machine prove to be a cost effective exercise? · Is it worth investing in redesign of the machine to improve reliability? · Is the machine and its components expendable and if so, should it be run into the ground? RCM has now been established in many engineering practices, but it’s most prominent in the airline field. Performing extensive maintenance on all the systems of a large airliner would not make sense as it would result in the aircraft spending more time in the hangar than it would in the skies making revenue. However, it’s critical to have a safe airliner and therefore, the maintenance process must not compromise safety in the resulting reliability. Although there are a lot of questions that are more ‘what if’ by nature, they can help to ensure that the right maintenance gets performed, giving the best possible results. Running through the RCM process on any complex hydraulic system can be both time-consuming and arduous. It’s a system that is most effective when performed on a fairly new machine with unknown failure causes. In summary, being able to detect problems early and therefore be able to extend the life of a hydraulic machine can save time, money and downtime. As engineers it’s our role to find a way to detect these problems and on some occasions, an RCM type approach can prove to be a valuable aid.