TPM 2: Optimizing Maintenance Effectiveness

TPM 2: Optimizing Maintenance Effectiveness

Rizzo, Ken

As we know now, Total Production Maintenance (TPM) is another major component of Lean Manufacturing. Lean’s mission is to reduce printers’ waste. TPM places the numerous equipment losses into six categories and those losses into three areas-equipment availability, performance, and quality.

Equipment Availability

1. Failure and Downtime-breakdowns and unscheduled stoppages

2. Equipment Setup-make ready

Equipment Performance

3. Equipment idling and minor stops-equipment not being used

4. Reduced production speeds-equipment being used at less than optimum speeds

Equipment Quality

5. Defective Product-production waste and spoilage

6. Reduced Equipment Yield-start-up waste and spoilage

To start eliminating the six big equipment losses, a program of maximizing equipment effectiveness must be developed and implemented. Equipment operators must be self-sufficient and self-directed or autonomous when performing maintenance activities. Autonomous maintenance effectiveness relies on small team activities and responsibilities.

Autonomous Maintenance is equipment operators in small teams performing the proper cleaning, lubrication, inspection, and maintenance of equipment and maintaining necessary conditions and specifications. To be effective, autonomous maintenance must be implemented in all departments, including prepress, printing, cutting, and finishing operations.

Process Improvement Teams consisting of equipment operators and maintenance staff should determine training needs and the necessary Critical Cares for equipment-cleaning, lubrication, inspection procedures and manufacture specifications and industry best practices. These procedures must be applied consistently to all processes and equipment for effective autonomous maintenance. If there is no maintenance department then the original equipment manufacturer (OEM) needs to be consulted.

Critical Cares. Printing equipment critical cares are the vital actions and activities required to maintain necessary equipment conditions and designed capabilities. They include effective cleaning, proper lubrication, inspecting for abnormalities, making proper component adjustments and settings, and maintaining manufacturer specifications.

Cleaning. This includes the removal of contaminations-dirt, water or impure matter-from equipment components and area to make neat and tidy, completely and thoroughly. Implementing proper cleaning procedures and techniques routinely will reveal significant abnormalities, and not require much more time than is currently being used for preventive maintenance.

Clean all sections and surfaces of equipment to remove dirt, dust, water, and other contaminations, which can cause increased friction, abrasion, reduced cooling, feed-line clogging, and electrical components failures. Among the major causes for equipment electrical failures is contamination from dirt and dust which affect electrical contact points, as well acting as insulators, which results in excessive heat buildup.

Clean equipment parts after lubricating: to remove excess lubrication and prevent contamination of production products. Proper cleaning is a condition of inspection.

Lubrication. It is important to put proper lubricants in or on specified equipment components to keep the components working freely. Properly lubricating equipment reduces chronic and sporadic failures. Neglecting lubrication causes mechanical seizures, accelerated parts deterioration, and abnormal overheating of components.

It is extremely important to apply the correct type of lubricant. Newer equipment may require a different lubricant than older equipment, even if from the same manufacturer. Less expensive lubricants may not meet the equipment OEM requirements for maintaining basic conditions.

Use the correct tools. Grease guns used to apply lubrication to specific equipment must be the right type, apply the proper amount of grease, and work properly. Automatic lubrication systems should be checked for proper operation. Consultation with the manufacturer is imperative concerning lubricants, lubrication tools, and auto-lubrication systems operation.

Inspection. Be sure to carefully look at, review, and determine if basic conditions are being maintained, equipment components are working properly, and specifications are being adhered to. Inspecting for proper operating mechanisms and components helps eliminate equipment failures and breakdowns. If specific equipment component inspections are included as part of the cleaning process, hidden problems-loose bolts, worn-out adjustment brackets, play in grippers and gripper system, poor roller conditions and settings, abnormal anilox chamber leaks, uneven and excessive pressure settings, tapes and belts deterioration-are revealed.

A single loose connecting part can cause abnormal vibrations and premature deterioration, possibly causing a total operational failure of the equipment. An abnormally operating transfer mechanism affects the system’s accuracy and usually creates non-conforming quality output. Sloppy movement and vibration can loosen other bolts, transfer mechanisms, and connecting parts, resulting in catastrophic equipment failure. If inking components, transfer mechanisms, print pressures, and connecting parts are not maintained, then accelerated deterioration of mechanical systems will occur and shorten equipment life.

Best Industry Practices establish the specifications for the proper operation of equipment. In prepress, equipment should be periodically inspected for CTP exposure system accuracy, damaged or deteriorated vacuum lines and seals, processor equipment operation, and plate punch square.

On presses, regularly check proper print pressures, roller conditions and settings, fountain solution chemistry and temperature, press in-feed and delivery performance, ink scumming and plugging, and any specific noises or abnormal generation of heat. Checking for excessive heat of various equipment components and materials periodically with an IR thermometer can identify potential mechanical problems before a complete failure occurs.

Abnormalities discovered by equipment operators must be accurately recorded in maintenance and operator logs and maintenance request forms. Management or the maintenance team can quickly prioritize and implement corrective actions to remedy the problem.

Specifications are statements, descriptions, desired conditions of all necessary settings, minimum and maximum sizes, and material requirements for effective operation of equipment. Proper equipment component settings will accelerate press makeready efficiency. Quick makeready depends on the elimination of as many adjustments as possible. The ultimate goal for make-ready is First Item Good.

Making accurate settings when changing from one job to the next will minimize the number of adjustments required to match the job’s register, color, and cutting specifications. Proper platemaking, true plate cylinder zero set, and plate mounting on press will accelerate makeready time and minimize press deterioration from excessive movement of machine components.

Correct printing pressures include the recommended plate/blanket squeeze, plate/anilox pressure, and the required impression cylinder and stock pressure for enough ink image transfer with minimal dot gain.

Poorly operated and calibrated inking, printing, cutting, and folding mechanisms will delay acceptable match to job specifications and substantially increase makeready time and paperboard waste.

Proper conditions must be maintained for the equipment to operate at its optimal designed capabilities. Computer control systems and electrical control panels must be maintained to prevent accelerated component failure. Temperatures and humidity should be kept within the manufacturer’s recommendations. Vibration must be within the limits of the equipment’s design, and dust and powder contamination must be totally prevented. Again, major contributors to accelerated equipment deterioration and failures include high temperatures or frequent temperature variations, paper dust, and spray powder contamination. Maintain consistent temperature and humidity levels year round in the prepress, printing, cutting, and finishing department environments.

In the offset pressroom for example, the areas for immediate focus could be the press roller systems and the sheet/web register/transfer systems. Pre-makeready-type procedures will address the fundamental issues that lengthen offset roller maintenance time.

* Use a schematic of the roller train for each unit and record rollers changed for future tracking.

* Have the roller supplier install the bearings on the roller shafts before shipping.

* Have all rollers and tools necessary to perform roller maintenance staged at the press during production.

* After the rollers are removed, clean the press-side frames and apply spray grease lubricants to the surface. Dried ink and other contaminants can more easily be removed next time.

Incorrect adjustments and poor maintenance subject equipment to conditions that greatly accelerate deterioration and lead to equipment failure. Factors that contribute to poor equipment condition include:

* Inadequate-or lack of-structured training and education for equipment management, staff, and operators

* Lack of or poor adherence to established preventative maintenance (PM) standards

* Fix-it-when-it-breaks programs

* Lack of effective process control standards

* Lack of enough of the proper maintenance tools

There are two basic types of equipment failure: operation-loss failure and operation-reduced failure.

* Operation-loss failures are sudden and total mechanical or electrical failures that shut down equipment and stop production all together.

* Operation-reduced failures include product defects and minor stop-pages that do not totally shutdown production, but cause equipment to operate at reduced quality and performance effectiveness.

To overcome the operation-loss and operation-reduced failures, there must be operator ownership of processes, effective preventive maintenance programs implemented, and a 5S culture established throughout all process.

Production performance is based primarily on the time available to operate and produce saleable cartons (crewed uptime and downtime), production operation performance (production per hour), and the amount of quality product produced (percent good to percent of waste/spoilage) that is accepted and paid for by the customer. Overall machine performance depends on operational and PM activities and eliminating waste in six areas.

Preventive Maintenance Analysis and Design

Preventive maintenance programs must be analyzed and designed to maximize machine productivity. Important issues for analysis include:

* Is the maintenance done according to schedule?

* Are the documented PM activities correct for the machine and performed effectively?

* Are the procedures and time spent on preventive maintenance efficient?

A preventive maintenance team-consisting of maintenance and production personnel-must analyze maintenance programs to determine what is being accomplished and how long it takes. If required, the PM team will then redesign current maintenance programs.

Review documented preventive maintenance programs. Maintenance procedures must be reviewed by the preventive maintenance team to determine if they are correct for the machine, if the instructions are clear, concise, and understandable for all operators, and if the amount of time required has been established and included in the documentation. Next, the OEM must review the documented maintenance activities. The OEMs can help to identify omissions, shed light on issues that are unclear, and suggest revisions to the PM procedures. Once the PM tasks are reviewed, revised, and approved, then evaluate what is actually happening on the machine.

Kalzen Blitz

In Japanese, Kaizen means to continuously change and make good. Kaizen events are extremely focused and intense improvement initiatives. A Kaizen Blitz creates an atmosphere and culture of continuous improvement by focusing the process people on solving the problems. Kalzen Blitz events typically are two to five days in length and require preparation before they begin. Kaizen events can target makeready and preventive and corrective maintenance activities. Kaizen event steps are:

1. Educate all operators and maintenance staff on how to perform preventive maintenance tasks correctly. Operators and maintenance staff should be tested using an established set of questions (based on the documented tasks and procedures) regarding PM on the machines. All operators should be able to demonstrate a basic understanding of how and why PM procedures are required. Is there a thorough cleaning of machine components? Are the components being properly lubricated? Are operators able to conduct basic inspections of components to determine if they are operating according to OEM’s designed capabilities? If not, then training is needed for everyone responsible for PM.

2. Establish the equipment PM team members for the event. Determine everyone’s responsibilities from the equipment crew to people conducting the timing of activities. Then execute the PM Kaizen event.

3. Record the time required to complete each PM task and activity. PM activities must be observed, timed, and then analyzed by maintenance and production departments. The goal is to determine how much value-added time (required for PM tasks) and non-value-added (wasted) time are being spent during maintenance activities.

4. Non-value-added PM time includes time spent searching for maintenance tools and supplies, determining who should do what, waiting on maintenance staff, machine operators watching but not assisting, and breaks. Document the non-value-added activities; record the amount of time wasted, and then work to eliminate it from the process. Non-value-added activities primarily revolve around a lack of planning and coordination of PM and what constitutes effective PM procedures. Begin with the basics, make sure that PM tools and supplies are correct, function properly, and are easily accessible. Take immediate corrective action if there are problems in any of these areas.

5. Standardize PM Activities. Final PM tasks and activities are now established (non-value-added activities have been removed) and the actual time to perform these tasks and activities are documented. The PM tasks and activities are now standard operating procedures subject to periodic audits.

6. Sustain the designed PM program by performing periodic audits of the PM tasks and activities. Audits must verify that PM documentation checklists are being followed and initialed, and PM team members know how to perform the required tasks and activities.

The key to analysis is through operator and maintenance staff teamwork working together to analyze and eliminate non-value-added activities. Then determine how much time is spent on value-added procedures, recording the actual time spent on the designed tasks and procedures which will result in more effective PM scheduling.

Implement the designed preventive maintenance program. Once the PM analysis has been completed and the designed procedures have been documented as SOPs:

* Compile the correct type and amount of cleaning, lubrication tools and supplies where needed.

* Standardize revisions to PM procedures and implement.

* Develop and implement maintenance training and education for machine operators.

* Make everyone accountable for PM effectiveness.

Establish PM program responsibilities and accountability. Preventive maintenance is a productive part of the process, not a service to the process. That’s why maintenance and production departments are equally responsible for PM effectiveness and the quality and efficiency of all production machines.

Maintenance department personnel need to be active participants at production meetings by reporting maintenance effectiveness data. The data should include OEM metrics, percentage of waste and spoilage, amount and type of breakdown occurrences, and the status of all scheduled PM projects. The question is not just PM effectiveness, but how much will it cost to replace equipment for not performing effective PM?

In summary, Total Production Maintenance provides the guiding principles, structure, and methodology to achieve real maintenance effectiveness and reduce equipment downtime, improve performance and increase capacity.

by Ken Rizzo, Director of Consulting, PIA/GATF

Ken Rizzo is PIA/GATF’s Director of Consulting and Center for Lean Practices. As an experienced process improvement specialist, certified in Six Sigma, ISO 9000 and Lean Manufacturing, Rizzo has over 35 years of commercial, label, and folding carton industry experience, including offset press operator and various production management roles. Rizzo developed the PIA/GATF Quick Response Makeready program, which is based on quick changeover methodology. Ken can be reached at krizzo@piagatf.org.

Copyright Graphic Arts Technical Foundation Dec 2007

Provided by ProQuest Information and Learning Company. All rights Reserved