Support to Autonomous Maintenance

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PM Element 1. Indicators

The measurement of the maintenance department is very important because this will help operators and tradesmen to visualize problems in the equipment, prioritizing activities and control the progress. In the beginning of TPM these Indicators are necessary.

1) Breakdown

Breakdown means any unexpected stoppage equals 10 minutes or more, when the component breaks or looses its function.

Tracking the number of breakdowns from the factory by line is required.

2) Downtime

How many hours have the equipment stopped due to breakdowns.

3) MTBF (Mean Time Between Failure)

To calculate this indicator divide the operational time of each line, machine or component by the number of breakdowns.

4) MTTR (Mean Time To Repair)

To calculate this indicator divide the downtime due to breakdowns by the number of breakdowns.

F-TAGS

All mechanics can fix a breakdown that means:

– Identify the problem

– Disassemble machine

– Identify the right spare part

– Perform repair

– Assemble machine

– Starting production

So for simple abnormalities, they must have the responsibility to plan that job and solve the F-Tag.

The idea is to have a faster system to solve simple abnormalities in the machines, preventing breakdowns.

They must be able to determine if external labor, or material is required, or if they can perform that job with the structure available in the factory.

F-TAG FLOW CHART

In this case tradesmen can plan and solve the abnormality. They can use production windows, change over or other type of opportunity.

PLANNED CORRECTIVE MAINTENANCE FLOW CHART

In this case tradesmen need help because they need an external expert to fix this machine, a long downtime or a spare part needs to be bought.

RESTORE  ORIGINAL CONDITION

In a factory with a bad maintenance system, some machines can be working in a bad situation. So the first step is to restore the original condition of the machine.

Imagine an old car, before an inspection standard begins to be applied, it is necessary to restore the original condition.

This is very important because a good Preventive Maintenance will not prevent failures in equipment with bad conditions. This will happen because the interval between the failures will vary too much.

BREAKDOWN RECORD

Explanation continued

COUNTERMEASURES TO ZERO BREAKDOWN

An important tool is to monitor what is causing the breakdowns: Forced Deterioration or Natural Deterioration.

Divide the causes for breakdown into 5 reasons:

1) Basic Conditions

2) Out of Operating Conditions

3) Natural Deterioration

4) Weak Point

5) Knowledge

Except for Natural Deterioration all other types cause Forced Deterioration in the machine. If we know what is causing the breakdown we can know which areas will need to be improved.

A short description of each type and some typical countermeasures are described in the next pages.

5 CAUSES TO BREAKDOWN

BASIC CONDITION

These breakdowns are related to:

– Lack of lubrication,

– Fasteners,

– Dirt and dust.

What would happen if:

– You don’t change the oil in your car for 100,000 miles…

– You change the tires of  your car and don’t tight the lug nuts…

– You don’t clean your tape player…

Example of Countermeasures

– Cleaning Standard

– Lubrication Standard

– Match Marks

Out of Operational Condition

These breakdowns are related to equipment being ran out of specified conditions:

– Typical specified condition might be: Temperature, speed, air pressure, hydraulic pressure,mechanical pressure, weight,

voltage, electrical amperage, etc…

What would happen if:

– You plug in your 110V hair dryer in a 220V receptacle…

– Drive your car with a pressure of 16 psi in the tires…

– Dry your cat in the microwave…

– Drive an Indy Car in the city….

Example of Countermeasures

– One Point Lessons

– Visual Control

– Match Marks

DETERIORATION

These breakdowns are related to natural deterioration of a component:

– Normally it is caused by friction and contact between parts, or  between parts and the environment.

What would happen if:

– You do not change the brakes of your car…

– You use the same shoe everyday for 2 years (don’t smell it)…

– Water flows in a pipe for 100 years…

Example of Countermeasures

-Autonomous Maintenance Inspections Standards.

-Planned Autonomous Maintenance Inspections Standards.

Deterioration Examples

WEAK POINT

These breakdowns are caused by components/ parts/ systems that were not correctly designed to support the operational conditions during the normal work. Normally the component suffers:

– Overload, overstress, overheating, chemical corrosion, accelerated wearing…

Examples:

– Ford/ Firestone tire recall,

– Shaft with 90 degree step down instead of radius in step down.

Example of Countermeasures

– Redesign.

Never modify machines without performing a 5 Why Analysis.

Fatigue Examples

FATIGUE FAILURE EXAMPLES

KNOWLEDGE (Lack of)

These breakdowns are related to lack of knowledge of:

– Machine operation,

– Machine repair,

– Installation.

What would happen if:

– You drive a Nascar car during a race today…

– You need to pilot a jet flight…

What happened when you drive for the first time?

Example of Countermeasures

– One Point Lessons

– Maintenance Standards

– Training

– Poka Yoke

COUNTERMEASURES TO ZERO BREAKDOWN

Classify the breakdowns in one of the 5 causes:

– Basic Condition

– Out of Operational Condition

– Natural Deterioration

– Weak Point

– Knowledge.

Generate a graph with the number of breakdowns for each cause. This graph will allow you to visualize if the factory has more forced or natural deterioration, and which actions can be done to reduce the number.

A factory with a high number of breakdowns due to Basic Condition will need to improve the cleaning standards, lubrication standard and visual controls for fasteners.

Otherwise a factory with a high number of breakdowns due to Knowledge will need to develop training and write a lot of One Point Lessons.

Since the breakdown is classified in one of the 5 causes, it is possible to identify a tentative countermeasure while a breakdown analysis is being performed.

These actions are supposed to be simple actions, that will allow the operators to identify the abnormalities preventing a breakdown. The tentative countermeasures generated would be:

– Inspection Standard,

– Cleaning Standard,

– Lubrication Standard,

– OPL.

The next flow charts give some suggestion of tentative countermeasures to be implemented.

Remember that tentative countermeasures are an extra help to reach Zero Breakdown, but not the end of work.

To reach the root cause and prevent the recurrence of the problem, a breakdown analysis is required.

TRAINING

During TPM implementation a lot of training will be required to improve operators skills, and also to transfer activities from Maintenance to Operation.

Training provided by maintenance can be divided in two categories:

1) Theoretical Training,

2) On The Job Training.

The Theoretical Training is better to apply when new concepts need to be taught to the operators and when activities are being transferred.

On the Job Training can be applied to teach simple tasks and to reinforce concepts from the theoretical training.

THEORETICAL TRAINING

Tradesmen are responsible to develop training materials, One Point Lessons or books, and also develop some models to explain the principle of operation of the systems that they are teaching.

This training always occurs during a line downtime, and they are supposed to be as short as possible

There are some examples of models in the next pages.

ON THE JOB TRAINING

On the Job Training in this context means train the operators during the normal operation of the equipment. Do not stop the equipment to perform these activities.

During the TPM implementation sometimes it is very difficult for the operators to identify abnormalities that can cause breakdowns in the equipment. It is possible to use the tradesmen to perform On The Job Training with the operator.

Once a week a tradesman goes to a machine and inspects a system looking for abnormalities and at the same time training the operator to identify this kind of problem.

Also On The Job Training can be applied after theoretical training to reinforce the concepts to the operators during the normal operation.

This training can be applied since Step 1 as “Abnormality Detection” training, and it needs to be a basic skill for the operators.

Remember: This training always happen during the normal operation.

MAINTENANCE INSTRUCTOR

Before TPM, the operators are normally focused on producing and only talk to tradesmen when they have a problem.

A change promoted by TPM is that the tradesmen need to train the operators.  Two methods can be used:

1) Theoretical Training,

2) On The Job Training.

During the implementation of the TPM Activities a lot of doubts will appear in the operators mind.

Tradesmen are in the factory 24 hours a day on any given operational day, so they could be available to teach the operators, and answer questions.

AM in the Workshop

Maintenance Workshops need to be an mirror for the factory. The tradesmen will be constantly asking for clean machines, and for the operators to inspect and lubricate the machines.

Applying Autonomous Maintenance in the workshop is a good way for the tradesmen to show the operators what is possible to achieve.

Tradesmen can also learn how to develop standards (cleaning, inspection and lubrication), that will make it easier for  tradesmen to understand AM.

In the next page are some pictures of a workshop applying Autonomous Maintenance.

Advanced Visual Controls

Advanced Visual Controls are used to visualize the evolution of deterioration in the equipment, and help the operators to identify these abnormalities.

The figures below show that is possible to use a simple coil to identify vibration problems, or a wrinkle to identify wear problems.

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