Preventive Maintenance

Preventive Maintenance

“Success does not happen, it is planned for”: Unknown

Someone has rightly said ‘Prevention is better than cure.’ During present times we are preventing ourselves from COVID-19 menace by keeping social distance and putting mask. Many people do yoga and meditation to remain healthy and calm. Majority of the mobile users put screen guard to prevent it from scratches.  

Something similar is true for any manufacturing or service sector, who conducts periodic and systematic preventive maintenance to keep their assets in healthy condition. Preventive maintenance is one of the key outputs of the Manufacturing Process Design Process. This process expects to keep the entire facility in a healthy condition.

Earlier there used to be a mindset ‘If it is not broken, don’t fix it.’ Studies estimate businesses spend 80% of their technician’s time working on reactive maintenance (breakdown) issues rather than performing preventive procedures. When we review the machine history card, in the majority of the cases, big problems are often caused by small, preventable oversights. Typically, an organization’s most devastating accidents, operational losses, and production setbacks are caused by maintenance systems and internal communication failures. This thought process may work in the short term but it incurs a loss of productivity, quality, cost and reputation in the long term.

Indeed, equipment failures cannot be eliminated—they will happen. However, smart preventive maintenance systems can reduce premature equipment breakdowns, keep employees safe, and even save millions in costs. Preventive maintenance means fixing small problems before they become big ones! 

However, preventive maintenance should not be performed on every equipment. The bottom line is that there is “no one size fits all” approach to maintenance. The costs of performing PM should always be less than the cost of failure. For example, say the cost of downtime for particular equipment is $500, and its PM cost is $800. In this instance, PM would be a waste of time and money. The company could save $300 by running to failure.

As per IATF 16949 clause 3.0, following are some of the key definitions

Preventive maintenance: Planned activities at regular intervals (time-based, Periodic inspection, and overhaul) to eliminate causes of equipment failure and unscheduled interruptions to production, as an output of the manufacturing process design.

Total productive maintenance: A system of maintaining and improving the integrity of production and quality systems through machines, equipment, processes, and employees that add value to the organization.

As per IATF 16949, Clause 8.5.1.5, one of the key maintenance activities is Preventive Maintenance.

4 Key Steps in Preventive Maintenance

1. Inspection

• Regular inspection ensures that equipment is safe
• Prevent workplace injuries
• Ensures that equipment is working as per the plan

2. Detection

• Detects problems early
• Reduces cost of breakdown

3. Correction

• A proactive approach to correct the defect before the machine fails
• Promptly addresses the problem

4. Prevention

• Learning from past mistakes and breakdowns
• Reduces stress and improves productivity

 Why preventive maintenance:

• To extend the useful life of an asset
• Prevent breakdowns from occurring
• Make repeated breakdown as zero.
• To ensure the predictability of the equipment
• To increase MTBF (Mean Time Between Failure)
• Reduction of MTBM (Mean Time Between Maintenance)
• Reduction of MTTM (Mean Time To Maintain)

When to do preventive maintenance: Based on the data related to MTBF, MTTR and output of process design.

• As per the objective of the top management
• It can be time-based like after every 3 months
• It can be usage-based like after running of 1000 hours
• Hierarchy of the machines based on criticality through brainstorming
• Cost of breakdown to the organization

Who can do preventive maintenance:  

There are 5 key systems in the majority of the equipment. They are Electrical, Mechanical, Pneumatic, Hydraulic and Electronic. While deciding about who can do the preventive maintenance, competence of a person on these 5 systems is pertinent to ensure effective preventive maintenance.

How to do preventive maintenance:

• Identify the resources and maintenance techniques needed
• Based on 5 key systems: Electrical, Mechanical, Pneumatic, Hydraulic and Electronic, identify the important checkpoints that need to be verified
• The checklist can be made from the inputs received from the manufacturer, machine manual, past experience, breakdown trend, the objective of the management
• Can be scattered throughout the year for different activities based on the performance like daily (CLIT-Cleaning, Lubrication, Inspection, Tightening), weekly, monthly, quarterly, half-yearly and yearly
• Determine the job plan like the scope of the work, list of necessary resources like tooling, manpower, drawing, safety instructions, operating procedures, spare parts

Key constraints of the management about Preventive Maintenance

• Budget
• Resources
• Time-consuming
• Difficult to manage
• Non-availability of spare parts

Key reasons for not giving importance to Preventive Maintenance

• Reactive maintenance is more cost-effective than preventive maintenance!
• Maintenance department does not have time for it
• Running Production is more important than preventive maintenance 

Key benefits of the effective Preventive maintenance process

• Diminish excess depreciation of the equipment
• Enhances the productivity of the manufacturing process
• Prevents untimely breakdown of the critical equipment
• Decreased equipment downtime and repair
• Increased equipment life expectancy
• Reduced overtime cost
• Improved safety and work conditions
• Less energy consumption
• Reduction of MTBM-Mean Time Between Maintenance and MTTM-Mean Time To Maintain

 Possible Challenges:

• How often preventive maintenance is actually conducted and not on paper?
• How often top management is interested in knowing the effectiveness of preventive maintenance?
• How often maintenance personnel are competent enough to understand the entire checklist (electrical, electronic, pneumatic, hydraulic and mechanical) and conduct PM accordingly?

References:

ISO 9001: 2015

IATF 16949: 2016

This is the 69^th article of this Quality Management series. Every weekend, you will find useful information that will make your Management System journey Productive. Please share it with your colleagues too.

Your genuine feedback and response are extremely valuable. Please suggest topics for the coming weeks.