How To Get It Right From The Start
Twenty best practises for improved maintenance in printing houses
Maintenance in printing houses requires a proactive approach, which involves close cooperation amongst all staff members and a well defined plan. The following article which is extracted from the best practice guide “Productivity Maintenance — how to run longer, leaner and faster” provides printers with a roadmap on best practices in maintenance.
Good maintenance practice:
The key to increasing productivity and profits
A clear relationship exists between productivity, reliability and maintenance
The primary dividends from effective maintenance are lower total operating costs (higher output and less waste), reliable on-time delivery and consistent product quality. In addition, effective maintenance preserves expensive equipment assets and reduces lifetime operating costs through minimising wear and replacement of parts. Good maintenance is also environmentally friendly (reduced energy, waste, cleaning materials, noise) and facilitates health and safety performance and compliance. Correctly set-up and maintained equipment is one of the prerequisites for process optimisation and colour management profiling.
A recent UK survey by Vision in Print (VP) found that all responding printers reported business benefits from improved maintenance – 90% found that it has reduced their press downtime and over 60% found they have a higher output with less waste, more consistent quality and improved safety. Those companies with a maintenance plan have a consistently higher performance in all areas compared to those companies without a formal plan.
Achieving a minimum maintenance level is 80% common sense combined with discipline and standard procedures – this is within the reach of all companies, irrespective of size, if they are prepared to make a small effort. However, many printers still have a very reactive approach to maintenance: when a breakdown occurs they deal with it. At the other end of the spectrum, some printing companies are using Total Productive Maintenance (TPM) to optimise equipment performance through integrating management, workforce and suppliers. However, it is unrealistic to think that the majority of printers could move to this level of sophistication – setting unachievable goals in a busy operation can be damaging and demoralising.
Maintenance: a cost or an investment?
Effective maintenance should begin with some fundamental financial management questions: Is maintenance regarded as a “necessary evil” or as an investment to increase productivity and reduce total operating costs? Are malfunctions only accounted for as direct repair costs, or is their total loss calculated (repairs, plus the costs of lost production, increased materials consumption, and consequential costs such as overtime, lost opportunities and unsatisfied customers)?
Progressive industrial companies incorporate maintenance as a total production cost variable and include downtime and consequential costs in their calculations. This financial management approach can provide substantial opportunities to reduce costs and increase profitability. A further benefit is that more saleable production capacity becomes available that can be converted into either increased sales or reduced capital investment — fewer machines to achieve the same production output.
Appropriate and consistent production data (Key Performance Indicators) is essential to reliably assess manufacturing and maintenance efficiency and identify areas where improvement action is needed. Many printers do not currently measure enough of the right data and some do not measure any at all.
New equipment technologies have reduced maintenance in some areas (automatic lubrication, self-cleaning sensors, roller and blanket wash-up devices). However, a prerequisite for achieving good results, for example from CIP3 press pre-setting systems, is that the inking and dampening systems are regularly and rigorously maintained. Some printers have replaced multiple machines with a single new high productivity machine that often runs 24 hours a day to maximise ROI. However, a consequence is that if there is a breakdown there is no production backup – making prevention of unscheduled downtime vitally important.
The central control systems of many machines can now provide condition monitoring and other useful service information. However, the potential benefits of these systems are often under-exploited. Equipment monitoring by either the printer or by the supplier over the Internet offers significant opportunities to provide effective remote services to identify malfunctions early and implement remedial action before production is interrupted.
Several low-cost information technologies are increasingly being used by printers: the Internet and digital cameras help improve speed and quality of response in predicting, diagnosing and fixing problems; identifying and ordering parts over the Internet 24 hours/7 days a week; using digital monitoring and diagnostic tools for effective low cost condition monitoring; and computer analysis can help identify maintenance priorities, costs and benefits.
Evolving maintenance techniques
Maintenance techniques have developed from breakdown response to preventive to predictive and proactive. Surveys show that as companies improve their maintenance as they shift from using only “fix it when broken” to restorative, planned preventative and condition monitoring. Companies using all these techniques have the most enlightened maintenance approach. The ViP survey showed a strong emphasis on preventative maintenance with a developing line of condition monitoring, and almost none rely only on a “fix it when it breaks” approach.
Operator involved maintenance (OIM) is a standard industrial approach used by many of the printers surveyed. Operators know their machines better than anyone else and, in the majority of companies surveyed, are the primary maintenance prevention and condition monitoring resource. Successful implementation requires “ownership” of the machine, delegation of responsibility, recognition, and teamwork with maintenance and scheduling staff. Maintenance needs to be adapted to the age and technology of equipment, operating hours, type of work and company organisation.
Productivity maintenance strategy
Maintenance by itself will be ineffective unless it is fully integrated into a company’s manufacturing strategy. Therefore, “Productivity Maintenance” should be seen as a key component of a manufacturing strategy to optimise productivity. This approach was developed by the Web Offset Champion Group as part of their international maintenance best practice project “Productivity Maintenance — how to run longer, leaner and faster”.
The payback from a successful maintenance strategy is improved manufacturing productivity that provides a competitive advantage. However, experience and research shows that there are no single, simple solutions. An effective programme will need about three years to become fully established as part of a company’s operating culture, although benefits should begin to flow within months of implementation.
The difference between better and poorer performing companies is that the best “do it”. Objectives should be oriented to a result (improved reliability, productivity, quality and less waste) delivered through optimised maintenance in co-operation with production. The desired results should be defined and measured to track progress. (Refer to Photo 1)
Photo 1:Three pillars of productivity Manufacturing efficiency is largely determined by how effectively the three pillars of productivity — Equipment, Materials and Operational Effectiveness — work together. Each pillar includes Standard Procedures, Maintenance and Environmental issues and poor performance in any one, for example maintenance, will negatively impact overall performance
Key success factors
1. Clear strategy from senior management to improve manufacturing performance that incorporates effective maintenance, including an appointed ‘champion’.
2. Staff motivation, supervision and training are an absolute requirement to optimise performance.
3. Plan maintenance time as part of production scheduling and respect times, priorities and procedures.
4. Monitor and analyse Key Performance Indicators (KPIs). These are currently an under-used tool.
The single most important factor is people – their management, motivation, training and selection. Changing staff attitudes and behaviour is important to promote team spirit, staff stability and equipment “ownership”.
How to fail quickly — lack of long-term senior management commitment, work on maintenance in isolation from manufacturing, not using KPIs effectively, and abandoning allocated maintenance slots.
Twenty best practice actions to improve maintenance
1- Decide to make Productivity Maintenance a key component in a manufacturing strategy to optimise productivity. Communicate the decision to all staff, appoint a person to be responsible for it, and provide adequate resources.
2 - Invest in people to get staff to understand why they need to work systematically – this requires motivation, education and supervision.
3 - Actions must start with the recognition both of the problem and that it takes money, motivation and time to fix. Benefits are significant and measurement is needed to keep the company focussed and motivated.
4 - Use Key Performance Indicators (KPIs) to help prioritise and plan maintenance resources to address specific needs. Select a few KPIs that are appropriate, accurate and consistent. Regularly monitor them to evaluate progress and communicate them to all concerned staff.
5 - Begin with an audit to define current plant status and identify the factors that limit performance and prioritise them – identify the 20% of the issues responsible for 80% of the problems.
6 - Plan and protect regular time slots for maintenance. Implement a policy that requires the manager to sign-off permission to abandon a planned maintenance slot.
7 - Establish programmes for prepress, press and postpress adapted to the age and technology of equipment, operating hours, type of work, company conditions and culture.
8 - Implement actions one step at a time – only when success has been established should the next step be undertaken. Eliminate reactive maintenance in 3-steps: Correction, Restoration, Prevention.
9 - Success requires teamwork between management, supervision and staff. Include appropriate suppliers within your team.
10 - Give operators easy-to-use maintenance checklists and procedures adapted to your equipment and operating conditions.
11 - Keep a maintenance logbook for each major piece of equipment. Add essential information (cleaning solvents, lubrication types used by the company, etc).
12 - Introduce Operator Involved Maintenance by providing motivation, training and supervision. Start with housekeeping and cleaning routines. Ensure cleaning techniques are adapted to the tasks required and use the optimum cleaning products.
13 - Put a magnetic white board next to each piece of equipment to note problems as they occur and to communicate them to the next shift. Prioritise which malfunctions to fix on an opportunity basis when there is a break in production. Put emergency service contact numbers here.
14 - Introduce an effective way to communicate maintenance requests to the right person (a magnetic board to ‘post’ maintenance requests or an intranet address).
15 - Ask your equipment and consumables suppliers for assistance. Discuss with them what maintenance services they can supply and consider the cost benefits on total operational performance.
16 - Consider negotiating supply contracts that provide service (and other) resources to your company, e.g. ensure optimum combinations of ink, fount and cleaning agents.
17 - Each company is unique in the resources it has available. Assess the available skills and how to best use them on different maintenance tasks; decide if dedicated maintenance staff are required; what mix of external services from OEM suppliers and independent companies is needed?
Photo 2:New information technologies combined with the Internet can provide effective remote services to identify malfunctions and assist remedial action.
18 - Establish a minimum spares inventory for each machine. The range and quantity of spares carried depend on the availability of back-up equipment, customer sensitivity to late job delivery and the time for urgent spares to arrive. If you directly purchase standard industrial components (electric motors, belts, electrical boards, PLCs, etc) make sure that you have the right reference number. Assess the risk of substitute parts to the consequences of any malfunction.
19 - Consider the application of new technologies in maintenance: Intranet and Internet service connections; digital cameras; condition monitoring and diagnostic tools.
20 - Fully use the capacities of equipment control systems. Most PCU-controlled equipment can help identify faults and more importantly continually condition monitor for emerging malfunctions. Review with your supplier how to organise this in-plant or by remote service.
(Refer to Photo 2)
Measure it to move it
Key Performance Indicators (KPIs) should be developed and evaluated by the staff who will use them. Regularly review to allow maintenance resources to be prioritised and planned to address specific areas needing improvement.
Production line output KPIs
Available machine time for production
Average net copies per hour
Average makeready time
Average waste (quality related)
Maintenance indicators KPIs
Non-scheduled/unplanned repair stops
% downtime due to breakdown
% e-work (a major cause of increased maintenance),
Mean time between failures Cost of parts and consumables used These two sets of data should be regularly evaluated to make the effectiveness of production and maintenance transparent. Coherent and clearly presented data provides operators, maintenance, managers and suppliers with an objective assessment of performance gaps and results.
The maintenance stairway
Maintenance techniques have changed over time from correction (breakdown) to prevention to prediction and pro-active continuous improvement.
Effective maintenance is a series of progressive organised steps over time to improve operational effectiveness.
The key step is the transition to proactive working.
Each maintenance technique is valid. Companies that optimise their maintenance select and combine the techniques that match the needs of their equipment and operations. (Refer to Photo 3)
| Photo 3:Maintenance Staircase
Maintenance is a series of progressive organised steps to improve operational effectiveness. The key step is the transition to proactive working.
Moving up the maintenance stairway
The decision as to what maintenance strategy to adopt is determined by its impact on the process, the availability of back-up equipment, customer sensitivity to late job delivery and the time for unplanned spares to arrive and to make repairs.
The application of maintenance also needs to be adapted to the age and technology of equipment, operating hours, type of work and company organisation. Printing plants have highly variable operating conditions and “one size does not fit all” — the same machine in different plants will frequently have different service, cleaning and maintenance needs. This means that different combinations of maintenance techniques should be used.
Moving up the maintenance stairway requires a planned approach that brings together the right procedures, tools and training and other resources for each step.
1. Corrective maintenance — “fix it when broken”
Most resources at this level are devoted to fixing emergency and chronic problems to keep presses running (“fix it when it breaks”). Safety is the highest priority to prevent accidents.
It is not necessarily wrong to use the “fix it when broken” approach for some processes. An in-depth study in the pharmaceutical industry concluded that drug manufacture is more cost effective if the production lines run until they fail: with a large number of identical production lines manufacturing can be switched while the failed production unit is repaired. This model applies in all cases where (a) there are many identical units performing the same task and (b) the company can cheaply accommodate spare capacity. In printing, this can be seen in office printers and may well soon extend to printers using multiple digital print units as their sole means of production. However, this approach is unlikely to extend to traditional volume printing except for some ancillary equipment; or in some cases where the machine capital cost has already been written off so the equipment is effectively free; and if the consequence of a stoppage has little effect on the delivery of the printed job.
The most significant drawback in this approach is the accumulation of multiple sporadic failures that cause unplanned press stops and undermine productivity in other ways. Although these stops are often only for short periods, they accumulate into a significant mass. Frequently these minor stops are either not recorded or incorrectly recorded, making it difficult to identify them and address the problem.
The general effect of relying only on corrective maintenance is the “spiral of breakdown despair”:
1) production loss from breakdowns and low productivity
2) equipment is worked harder to recover lost production
3) breakdowns increase and more time is lost
4) increased production pressure reduces maintenance time.
(Refer to Photos 4,5)
Photo 4:White board/Quad
An autonomous maintenance white board is kept up to date by the press operators to help prioritise their maintenance actions. These are made either at planned maintenance periods or as smaller tasks during press stops.
|Photo 5: Spiral of breakdown despair|
2. Restoration maintenance
Photo 6: Glazed/Bottcher
It is pointless maintaining something in poor condition because this often results in repeatedly fixing the same problem and has little effect on improving underlying productivity – in other words a waste of resources. It is essential to return equipment to its original condition so it can be maintained normally. Firstly, focus on chronic minor breakdowns that collectively often total the highest amount of lost time. Sudden sporadic breakdowns with long downtime are usually the result of deterioration over time – restoration is the main way to reduce these.
(Refer to Photo 6)
3. Planned preventive maintenance
This is a routine cycle of scheduled maintenance using standard procedures and reporting to minimise failures. Key actions are: introduce a planned strategy; start an Operator Involved Maintenance (OIM) programme; track failure rates of wear parts; build a repair history database and develop a parts inventory from it.
Cleaning, inspection and lubrication
There is a strong correlation between good housekeeping and maintenance. Therefore, it is no surprise that 89% of ViP survey respondents consider their plant to be moderately clean and the remainder very clean. Regular cleaning (with equipment inspection) and lubrication are fundamental to productivity maintenance and are routinely performed by operators. Over 75% of plants clean their equipment at least once a week and usually every shift. Lubrication is normally monthly and in some cases weekly. Companies with a maintenance programme tend to have their operators clean and lubricate their machines more frequently.
(Refer to Photos 7,8,9)
|Photo 8: Accumulated ink and paper debris is a major cause of unscheduled stops and malfunctions||
Photo 9: Dust/MEGTEC
Operator involved maintenance (OIM)
OIM is a standard industrial approach designed to give operators better understanding in preventing problems and to free up dedicated maintenance resources. Operators know their machines better than anyone else and the essential goal of OIM is to get them to take over certain maintenance tasks. Their responsibilities usually include:
• Regular cleaning, inspection and lubrication (5 Cs) to slow and detect deterioration.
• Regular monitoring of equipment condition.
• Condition monitoring to detect faults as early as possible.
• Understanding and application of standard operating procedures.
• Make small service actions on an opportunity basis and assist maintenance staff for more important interventions.
• Continuous improvement may also be added in the most advanced working environments.
• OIM actions are made at regular planned maintenance periods and as smaller tasks carried out during machine stops. Successful implementation requires a series of steps over time, encouraging “ownership” of the machine, delegation of responsibility, recognition and teamwork with maintenance and scheduling staff. Training is essential for success.
4. Predictive maintenance and condition monitoring
Few components have a specific lifetime. Usually there is a long failure development period before a breakdown occurs. Condition monitoring uses different tools that predict early component deterioration to initiate maintenance sooner so that remedial action is cheaper, faster and without unplanned production stops.
Many of the printers participating in the ViP survey are using some condition monitoring with good results — ranging from training operators to use their ‘built-in sensory systems’ to the use of dedicated tools. The cost of digital monitoring devices has fallen making them more widely accessible. Many of these tools allow measurements to be recorded and exported to a computer system to simplify trend analysis.
The first step is to establish the normal operating levels of component characteristics and the time between detection of abnormal conditions and failure. The keys are:
• Detection: at the onset of change to active deterioration.
• Diagnosis: type, severity and location.
• Decision: what to do and when.
Condition monitoring methods include using performance data, vibration monitoring, power consumption, lubricant and wear debris monitoring, visual and sensory inspection.
Begin with staff – people are important maintenance assets because they are naturally equipped with built-in condition monitoring system that can feel, hear, see or smell small changes. Even some of the most advanced systems used by the military accept that operators can frequently provide the best early warning of failure due to their ability to simultaneously compare multiple inputs — something that neural network technology is only barely able to mimic. If correctly trained, operators can identify deterioration in equipment operating condition. Staff will become more efficient if suitable monitoring tools are available to them.
(Refer to Photo 10)
Photo 10: Monitoring components and detecting the onset of failure characteristics (higher vibration, operating temperature, power consumption, changed oil condition) allows scheduled repair prior to break down.
5. Continuous improvement
Best practice is a virtuous circle of evaluation, development, instruction, monitoring, management and improvement. The objectives are to focus on high cost priorities to simplify systems, increase efficiency, provide cost-effective maintenance thereby extending equipment reliability and productivity. Each issue needs a champion responsible for setting objectives, documenting actions and results and leading a cross-functional team. A wide variety of techniques are used including Kaizen, Six Sigma and Root Cause Analysis. Life Cycle Analysis (LCA) integrates all lifetime operating factors (energy consumption, downtime, production speed, maintenance, parts, waste, buildings, etc.) into an economic system to optimise total cost. The significant potential to reduce overall costs has been recognised by some printers who use LCA with TPM programmes to help them decide their purchase and manufacturing strategies.
(Refer to Photo 11)
Photo11: Monitoring/Sun C
Condition monitoring tools
Digital technologies can assist in condition monitoring to detect faults before their symptoms become physically apparent. The cost of digital monitoring devices has fallen. Most allow measurements to be recorded and exported to a computer system to simplify trend analysis. Before buying a tool check with other printers, or suppliers, about which models offer good value, are reliable and easy of use. Some considerations include:
• Select 1 or 2 tools for key needs and work with them for about a year until their utility is demonstrated (introducing too many tools simultaneously often leads to poor use and unrealised expectations).
• Tools must be used correctly with appropriate training and tool calibration.
• Use the tools regularly and record their readings into a data format that allows trend analysis to help plan actions and provide feedback to management and staff.
Tools that are economic and used by most printers include:
Ink & dampening measurement tools: Digital conductivity meter, pH meter, thermometer; Hydrometer (IPA %), water hardness tester, Shore hardness meter, roller stripe measuring card, blanket packing and thickness gauges.
Infra-red guns: Temperature variations have a significant effect on performance and reduce component life – a dirty electric motor running at a 10°C higher temperature as a result of blocked airways may have its life reduced by 50%. IR guns can be tuned to specific wavelengths to measure surface temperatures of components (rollers, fountain pans, plates, blankets, dryer, chill rolls), and to locate loose electrical connections, hot motors, and bad bearings. Benchmark readings should be recorded when the machine is running correctly and regular measuring will identify any deviations that are early symptoms of problems.
Digital ultrasonic scanner: An efficient tool to identify compressed air leaks and to assess rolling element bearing condition to identify potential failures. When equipped with earphones operators can hear the vibration patterns of different components (a modern version of a stethoscope). Ultrasound is also a good technique to determine optimum lubrication because the signal changes during greasing and pumping is stopped when the sound level returns to its normal benchmark level.
Digital camera: To record images of maintenance procedures and problems. These can be sent by Internet to help diagnose complex problems more quickly and reliably.
Remote site services: Many suppliers have modem services to monitor equipment running trends and review fault reports to provide an early warning of downtime risk and to plan preventive action. These are increasingly available over the Internet to eliminate the need for dedicated and costly ISDN lines.
Information availability: Manuals should be available to all staff at all times (with back-up duplicates stored separately).
Test forms: Measure press impression performance (FOGRA, Systems Brunner, GATF, and IFRA). Uses include analysing a specific quality problem, monitoring output quality annually and materials testing.
More sophisticated tools include: oil analysis, thermographic cameras, accelerometer, vibration monitoring, stroboscope, manometer and laser alignment.