12 Factors for Machine Life

Focus on machine management through maintenance, repair and rebuild actions

Construction Equipment - June 1, 2005

Mike Vorster
Contributing Editor

Replacing an oil filter and replacing an engine both take time, cost money, and keep the machine working. The two tasks are, however, different: Replacing the filter is a maintenance action; replacing the engine could be either a repair or a rebuild.

There are important differences between maintenance, repair and rebuild actions. Let's define what the terms mean and see what can be done to improve performance in each area.

•Maintenance actions ensure that machines start at the beginning of each shift, work when needed, and don't break down. They focus on the prevention of failures and the reduction of collateral incidents that occur when breakdowns disrupt production. These maintenance actions fall into two distinct categories: preventive and mechanical.

Preventive maintenance includes the routine checking and changing of fluids and filters as well as all the inspections and adjustments needed to keep everything in working order. Mechanical maintenance goes much further. It includes the work done to repair or replace major components before failure and is based on periodic inspection, wear measurement, and condition assessment.

Maintenance is an act of faith. Nothing needs to be done right now; the machine could work for another day or for another month before it breaks down and demands immediate attention.

Even so, successful equipment managers know that an effective preventive maintenance program is a must. They know that it is an investment rather than a cost and that success depends on three factors:

1. Preparation. Technicians must have the complete and thorough check lists, diagnostic tools, filter kits, materials, and supplies necessary to ensure that the work is done thoroughly and efficiently.
2. Discipline. Systems and resources must be in place to plan, schedule and perform the work as required. There can be no compromise on the need to complete the work to the required standards at the required time.
3. Feedback. Reports from field technicians must record work done and note any additional action to be taken. Reports must be reviewed and additional work must be planned, scheduled and performed as soon as possible.

Mechanical maintenance focuses on replacing major components before failure, rather than after, and bridges the gap between preventive maintenance and repair. (See February 2004, p. 91.) Effective programs rely on three factors:

1. Information. Feedback must be used to gather information on the condition and remaining life of all major components. Sources include the preventive maintenance program, oil samples, wear measurements, and the best techniques available for condition assessment.
2. Understanding. Managers must know the life of all major components and appreciate that both the direct cost of repair and the collateral cost of failure can be reduced by replacing before failure as opposed to waiting for the failures that ultimately define maximum component life.
3. Confidence. An understanding of remaining component life and an appreciation for the consequences of on-shift failure help give the confidence required to implement a mechanical maintenance program and take action before failure in order to prevent failure.

•Repair actions take place after failure. There is little option but to spend the required money and return the machine to working order as quickly as possible. When, where and how is not really under our control: The loader has broken down, the trucks are standing idle, and the batch plant is about to run out of aggregate. It is time for action rather than careful thought and for saving time rather than cost.

Breakdowns and the resulting repairs are a manager's worst enemy. Time is, in most cases, more important than quality, and it is not unusual to have two or three breakdowns occur before a problem is properly diagnosed and fixed.

The frequency with which repairs occur should be minimized, and every effort must be made to implement a proactive program that focuses on inspection and prevention rather than repair. (See January 2005, p. 91.) When breakdowns occur, managers should focus on the following three factors:

1. Keep a cool head. Repairs require speedy action, not panic. Cost, caution and, above all, safety must not be forgotten in the rush to accomplish the job. Look to a replacement machine, look to a way to complete the work some other way, but never look to a makeshift unsafe operation.
2. Find the cause. If there is no diagnosis and no mechanism to address the cause, then the failure will, almost certainly, happen again. Finding and eliminating the cause is as important as repairing the machine.
3. Don't compromise. Compromises in replacement parts, procedures, cleanliness and quality work will result in repeat work. There is no reason to build the cause for a second breakdown into the action taken to fix the first.

•Rebuild should not be confused with repairs. Rebuilds can be done either before or after failure and must be carefully planned and executed. The objective is to improve the reliability and uptime of the machine and to extend its life for an appreciable period. The entire machine should be analyzed and careful, deliberate decisions made regarding the scope of the work, the costs involved, and the performance expected once the rebuild is complete.

The decision to invest a considerable sum to rebuild a machine is extremely complex. There are no rules that guarantee success. Both the timing and the extent of the work done during a rebuild need discussion, keeping in mind these three factors:

1. Machine design. Some machines are more "rebuildable" than others. They have simple, robust frames; clearly defined components; and have been designed to accommodate a future rebuild. Machines without these characteristics are difficult and risky to rebuild as there is little inherent quality available to support an extended life.
2. Planning. A rebuild is not a series of major repairs. The process must be carefully planned and considered. The remaining life on all major components — especially the frame and other structural components — must be evaluated to ensure that the machine as a whole is capable of reliable performance for an extended period.
3. Set goals. There must be a clear understanding of what will be done, the budgeted cost, and the additional performance expected from the machine after the rebuild. The action taken to rebuild a paver for one more season is different from the action taken to rebuild a rigid-frame truck for 6,000 additional hours.

Dozens of filter changes and possibly a rebuild occur over a machine's useful life. The effective management of that life depends on the proper execution of maintenance, repair and rebuild decisions.

Machine Management Categories
Action	When we do it	Why we do it	Key factors
Success starts with an effective preventive maintenance program. But excellence depends on how well a manager comprehends and executes the key factors in each facet of an overall machine-management program.
Preventive Maintenance	Before failure, to a set schedule	To ensure that fluids and filters are checked and changed and that adjustments are made as necessary	Preparation Discipline Feedback
Mechanical Maintenance	Before failure, when failure is predictable	To keep the machine up and running, prevent breakdowns, maximize reliability, and minimize downtime	Information Understanding Confidence
Repair	After failure	To return the machine to work and resume production as quickly as possible	Keep a cool head Find the cause Don't compromise
Rebuild	Either before or after failure	To extend the life of the machine as a whole and improve reliability and uptime	Check machine design Plan the process Set goals