May it be a machine, plant or human relationship, “MAINTENANCE” is always economical than repair!

Maintenance of machine and equipment, over the years has undergone a significant shift. It is no more viewed as an expense. Rather, a more positive approach considers plant maintenance a profit center, which is critical not just to reduce overall operating cost, but also to boost productivity of the plant in a big way. The key to this approach lies in a new perspective of proactive maintenance in lieu of conventional predictive and preventive methods.

This article analyses several maintenance strategies and process presently available with an attempt to predict the path ahead.

Cost of maintenance:

There is an increasing concern about higher maintenance cost and maintenance productivity. Some large screen printing companies have revealed that maintenance is the single largest manageable expenditure in a plant. Although many agree that maintenance strategies such as preventative and predictive methods have resulted in production savings or up to 25%, studies have also shown that 1/2 of the maintenance cost can still be saved.

Typically, maintenance cost can be divided into two main groups – direct costs and indirect costs. The first group relates to costs on labour, materials, services and maintenance overhead. The other group i.e., hidden costs or indirect costs, i.e.,spares & replacement, can be classified.

Under the following six big losses if you fail to maintain screen printing machines and equipment, it might result in loss of productivity

• Breakdowns and unplanned v plant shutdown losses
• Excessive set-up, change overs and adjustments losses
• Idling and minor stoppages
• Running at reduced speed
• Startup losses
• Quality defects

Maintenance is defined as an activity carried out for any screen printing equipment to ensure its reliability to perform intended functions. It can range from simple repair of any screen printer that has failed to keep it running, to restoration of its favorable operating condition. Over the years, many new strategies have been implemented for maintenance. These are intended to overcome the problems related to screen printing equipment breakdown. Some of the common maintenance strategies are discussed below:

Breakdown maintenance

One of the earliest maintenance programs to be used in the industry, this approach to maintenance is reactive and calls foraction only when the equipment needs to be fixed. The strategy is to apply only the corrective maintenance activity, which is required to correct a failure that has occurred or is in the process of occurring. It involves no routine maintenance task and is also referred to as no scheduled maintenance strategy. Thus, this activity may consist of repairing, restoration or replacement of components.

Preventive maintenance

This is a time-based maintenance strategy where on a predetermined periodic basis; the equipment is taken offline, opened, and inspected. Based on visual inspection, repairs are made, and the equipment is then put back online. Under this strategy, replacing, overhauling, or remanufacturing of an asset is done at fixed intervals regardless of its condition at the time. Although this is a well-intended strategy, the process can be very expensive. Nevertheless, some preventive maintenance is necessary as some regulations require annual / biannual inspection to be conducted.

Predictive maintenance

It is a more condition-based approach to maintenance based on measuring the equipment condition in order to assess if it will fail in the future some time and then taking action to avoid the consequences of that failure.

Proactive maintenance

Unlike the above three strategies, proactive maintenance provides a new approach to plant maintenance. In contrast to preventive maintenance (based on time intervals) or predictive maintenance (based on condition monitoring), proactive maintenance focuses on the monitoring and correction of root causes to equipment failures. Proactive maintenance strategy is also designed to extend the useful life of the equipment to the wear-out stage by adapting a high mastery level of operating precision.

Proactive vs preventive/predictive

In recent years, proactive maintenance has emerged as one of the most important means of maintenance because of its unsurpassed cost savings when compared to conventional maintenance techniques. Unlike predictive/preventive methods, proactive maintenance prescribes corrective actions aimed at root causes of failure, not just symptoms. Its main objective isto extend the life of screen printing machines & equipment as opposed to

1. Making repairs when often nothing is broken,
2. Accommodating failure as routine and normal, or
3. Preempting crises failure maintenance in favor of scheduled failure maintenance.

Type of Maintenance Strategy for screen printing shop