Part 2: Reactive and Run to Failure Strategies

The terms run to failure and reactive maintenance are often, incorrectly, used interchangeably. The concept of reactive maintenance is to run equipment until if fails and then figure out how to repair, replace or ignore it. This is the prevalent maintenance practice which has significant impact on business profitability. On the other hand, RTF is a strategy which, when performed correctly, can manage assets with a reduced impact. While not as extensive or cost effective as a PdM or CBM program, the philosophy still requires planning and thought.

With highly critical equipment, the plan may be to apply a combination of planned and condition maintenance to reduce the risk of failure. The remaining equipment is often left to fend for itself. This mistaken concept of twisting RCM and similar maintenance development tools has resulted in significant negative impact within industry. Less and non-critical equipment was not meant to be excluded from maintenance by these strategies, just a different level of application!

In an RTF program, the concept is to perform some methods of inspection, testing, maintaining, or other method that can identify that a problem is occurring such that action can be taken. This may be planning as part of an outage or staging parts and materials for when the failure occurs. The result is improved control of the repair related costs and improved inventory practices. In an environment where maintenance is being cut, or a full program for critical equipment does not exist, such a program can assist in assuring a higher state of readiness than just allowing equipment to fail. Who has not had the experience of going to find parts for equipment during a failure only to find the parts are obsolete?



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The Case for Reliability: Part 1

Starting in the latter part of the 20th Century companies focused in the reduction of inventory as part of their cost reduction strategy. Such product and MRO inventories were the result of internal and external bottlenecks and equipment maintenance. The primary strategy was, and still is, Run to Failure (RTF) and reactive maintenance. The challenge is that both RTF and reactive maintenance require spares inventories that can be significant. The reduction of maintenance and MRO inventory are mutually exclusive.

What started as intelligent modifications to inventory became dramatic change as the principles of industrial and reliability engineering became sloppier. In extreme cases, maintenance or operations personnel would order double of everything and hide the extra in workshops and toolboxes or the opposite where inventory would be stripped bare. Indications of MRO gone amok include spare parts hidden by personnel through the facility or significant amounts of repair work in-progress hidden through repair vendors. For instance: motors for repair at vendors with no decision until they are needed, then processed as urgent or emergency.

The status of the inventory in a reactive type program is also driven by the last significant emergency that drew senior management attention. Even when the fault would be a low future risk, a knee-jerk reaction exists and expensive spares or components are stocked taking up space and resources. In the past decade I have seen a dozen instances of the exact following case in commercial, industrial and government facilities world-wide: a failure some 20-30 years in the past of anelectric motor winding that had a significant impact and long repair time. A full set of windings or field coils is purchased and put into storage (almost always incorrectly stored). The winding fails 20-30 years later and the coils are pulled for use at the repair facility and the coils are found to be too aged or damaged for use.


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