The success of most manufacturing businesses hinges on efficient processes and reliable plant and equipment. Break downs and down time can have far-reaching implications on the success of a business. Maximising operational efficiency can have a significant impact on overall success. That’s where TPM, or Total Productive Maintenance, comes in.
What is TPM?
TPM is an approach to equipment maintenance which provides a consistent and repeatable methodology for continuous improvement. It is a powerful quality and process management method, especially meant for companies with lots of machines that involve high maintenance costs. The outcomes of TPM can be summarised as:
- Improved equipment performance
- Increased equipment availability
- Improved overall productivity
- Reduced emergency downtime
- Reduced maintenance costs
- Reduction in customer complaints
- Increased overall return on investment
- Increased employee skill levels and knowledge
- Increased employee empowerment and job satisfaction
- Improved safety and accident reduction
- Improved core business processes.
The goal is maintaining – and improving – productivity and keeping emergency and unscheduled maintenance to a minimum. Fewer breakdowns, stops, slow running and defects can result in many of these aims being quickly achieved. The key to success is preventing equipment problems occurring in the first place by identifying potential causes and carrying out proactive and preventative maintenance.
Central to the concept of TPM is the understanding that everyone is responsible for the day-to-day maintenance of machines, not just the maintenance team. Operators become involved in maintaining their own equipment, creating a sense of shared responsibility.
How does TPM work?
There are six big common causes of lost productivity in manufacturing: unplanned stops, setup and adjustment, small stops, slow running, production defects and reduced yield. They provide a starting framework for thinking about, identifying and attacking productivity loss.
The focused improvements brought about by TPM includes three basic improvement activities:
- Equipment is restored to optimal condition
- Equipment productivity loss factors are determined and eliminated
- Learnings from the restoration and loss elimination processes provide a definition of optimal machine condition that can be maintained and improved through the lifetime of the equipment.
The traditional TPM model is based on a foundation called 5S, with eight supporting activities (pillars).
The 5S foundation creates a work environment that is clean and well organised. The theory is that this makes it easier to find things and to spot any emerging issues. It is based on five steps:
- Sort – remove anything not needed from the work area
- Set in order – organise everything that’s left
- Shine – clean the work area
- Standardise – create standards for the above areas
- Sustain – keep it up!
The 8 Pillars are proactive and preventative techniques for improving equipment reliability:
- Autonomous Maintenance – operators are in charge of routine maintenance tasks and inspection. This gives them more responsibility, increases their knowledge of the equipment they use on a daily basis and makes it more likely that potential issues will be spotted early on.
- Planned Maintenance – scheduled maintenance tasks that reduce instances of unplanned stops and enable better inventory management of spare parts.
- Quality integration – apply route cause analysis to eliminate recurring problems and reduce cost by catching defects early.
- Focused improvement – employees work together to achieve regular, incremental improvements to equipment operation.
- Early equipment management – use knowledge gained above to improve design of new equipment, reducing start up issues.
- Training and education – fill in knowledge gaps to develop skills of operators as well as maintenance teams.
- Safety, health and environment – maintain safe environments to achieve the target of an accident-free workplace.
- TPM in administration – reduce waste in administrative functions and support production through improved admin operations.
How is it measured?
It’s vital to be able to measure and track improvements resulting from TPM – otherwise how can you possibly know whether your efforts have been worthwhile? OEE (overall equipment effectiveness) is a basic measure associated with TPM. It identifies the percentage of planned production time that is truly production.
The goal is 85 – 100%, with 100% representing perfect production where machines always work at full speed and deliver products of perfect quality. It’s not unusual for manufacturers without TPM to be around 40% – which represents a huge scope for improvement.
Under OEE, there are five pieces of data which need to be recorded: stop time, planned production time, ideal cycle time, total count and good count. This can be done manually, but it’s much more accurate when automated. We won’t go into the detail of each of these here, but it’s important to be aware of this process to understand how TPM can work in a practical sense.
Practical steps to implement TPM
There is a lot of theory, along with various tools and methodologies associated with TPM which help in its implementation. Rather than going into huge detail here, we’re going to outline a simple step-by-step process to begin to embed TPM within your organisation.
Step 1: Identify a pilot area
You will need to select a piece of equipment to begin the process. If you’re new to TPM, picking the easiest to improve is usually a sensible choice. If you’re more experienced, or have engaged an expert to help, picking a current bottleneck can be a better option.
Create a visual activity board in an easy-access area so everyone involved can see the problem being solved, the current situation and cause, actions to address this, improvement targets and any remaining problems. This can be a place to share learning between teams and encourage, support and motivate team members, as well as to celebrate success.
Step 2: Restore equipment to prime operating condition
Start with the first three steps from 5S (sort, set in order, shine) to prepare the area for improvement. Take before and after photos for your activity board. Create a checklist and audit schedule for steps 4-5 of 5S (standardise and sustain) and make this available to all.
Step 3: Initiate an Autonomous Maintenance programme
Operators and maintenance personnel agree which recurring tasks can be productively performed by operators – some light training may be required. There are a few preparatory steps which can be carried out now to help make this step run smoothly, for example:
- Key inspection points can be identified
- Opaque guarding can be replaced by transparent guarding (if safe and feasible) to make inspection points more visible
- Document set points can be identified and visual aids added to the equipment
- Lubrication points can be identified and a schedule set
- An Autonomous Maintenance checklist can be created and periodic audits scheduled to verify the checklist is being followed.
Step 4: Start measuring OEE
This recording must include unplanned stop time reason code tracking to give a clear picture of where productive time is being lost. Data can be analysed to identify the most significant cause of lost production time, and the TPM concept of Focused Improvement (Kaizen) can be applied to create a multi-disciplinary team to address the problem.
This involves collecting detailed information on the symptoms of the problem, organising a problem-solving session to identify the most effective fixes, scheduling machine stop time to implement the fixes and then monitoring of the results.
Step 5: Use the TPM concept of Planned Maintenance to introduce Proactive Maintenance Techniques
This can include identifying components that wear or fail and scheduling suitable maintenance intervals based on existing knowledge. The condition of components at time of replacement should be monitored in order to review the process over time and to adjust if necessary.
Step 6: Reward staff
This is not an essential step, but employee participation is key to success and ongoing improvement under TPM. Keeping staff engaged with a monthly award for the Best 5S Area, or Best Improvement, for example, may help.
Other TPM activities, such as Quality Maintenance and TPM in Administration can be slotted in when needed, but this forms a basic process to get you started.
If you’re new to TPM, working with a specialist with practical experience to get things up and running will really help you get to grips with the process involved. It can also help with encouraging staff engagement and a smooth transition as you ask staff to take on extra duties. Why not give Padgate Services a call to find out how we can help?