Planned preventative maintenance and condition-based monitoring

This article is written to meet the following sections of the Standards:

Contents

• Scope
• Maintenance systems
• Planned preventive maintenance (PPM)
• Condition-based monitoring
• Risk assessment
• Scheduling
• Communication
• Records
• Review

The purpose of a planned preventative maintenance system, or PPM as it’s known, is to prevent equipment from failing which could cause contamination of the product and impact customer orders.

Planned preventive maintenance (PPM)

PPM is a system of scheduled maintenance which is designed to prevent the equipment from failing. Maintenance tasks are carried out at a set frequency, to service the equipment and stop it from breaking down.

Risk assessment

The frequency and type of maintenance tasks must be based on a documented risk assessment which considers the manufacturers guidelines and the likelihood and severity of failure.

This means that an assessment must take place which identifies all the pieces of equipment and any facilities that need to be included in the PPM system.

Once this list has been established, each piece has to be risk assessed to identify the frequency of maintenance. And whether typical service-based maintenance is best, or if condition-based monitoring can be used.

Critical spares

Part of the risk assessment should look at what spares are critical to ensuring that the process keeps running. These are parts which would mean that the process would be down for a long period of time – if they were to fail. This may be because the parts have a long lead time, or the time required to replace the part is longer than wanted.

Spare parts

Ensuring that there’s a good stock management system in place for spares is also another essential part of a good PPM system. This means that the engineering function needs to know and list all spares that are required, ensure that the required quantity is in stock (based on the likelihood of failure) and then implement a stock control system to manage them.

Communication

Relevant staff must be consulted when maintenance or repairs are to be completed in product areas. This is to ensure that the product isn’t put at risk.

Missed jobs

Where a task hasn’t been completed to schedule, there needs to be a process which ensures that it doesn’t get missed altogether. For example,

• Should that job go to the top of the pile when the next lot of work is completed? Even if this means, more important jobs may get put back by doing so?
• What happens when you get a back log of work?

All these scenarios need considering and a process putting in place to manage them, if and when they do happen.

Review

An effective maintenance system must provide the following benefits:

1. Minimise contamination risk to product.
2. Minimise breakdowns which will reduce the impact on customer orders.

Maintenance objectives must be in place to monitor the above benefits by tracking KPI’s such as:

• Foreign body incidents caused by equipment.
• Breakdowns – the number and frequency.
• Completion of maintenance tasks to schedule.

KPI tracking and trending of this information should highlight where improvement is needed.

100-year fix

It’s common for companies to get into a cycle of firefighting breakdowns, which means that the PPM system tends to slip. This is then compounded by the fact that the breakdowns are fixed as quickly as possible and then forgotten. This tends to mean that the fix – is more of a sticking plaster type of fix, rather than a 100-year fix.

This is where thorough root cause analysis can save the company time and a lot of money. Really spending the time on finding out why the failure occurred in the first place and fixing the root cause, will reduce breakdowns. Which in turn will reduce downtime. This then allows the engineering team work on proactive maintenance, rather than firefighting.