Managing productive maintenance: best practices to eliminate equipment failures and maximize productivity

Preface

More organizations, if not all of them these days, have been pressured to remain competitive in rapidly changing markets. They have been confronted with the customer ’s increasing demands for near-perfect quality and on-time deliveries of their products. Those pressures have brought renewed concerns about their own internal efficiencies and productivities, and inquiries about how they will be able to survive in markets that are becoming harder and harder to serve. Additionally, there are increasing pressures to perform on safety and to be fully compliant with stricter environmental rules and regulations.

Asset-intensive industries fight continually to get all the utilization they can out of their aged or even brand-new facilities, with as much efficiency as possible. There is generally very little capital available to invest, and an even tighter squeeze on manufacturing costs of every budget cycle. Companies operating in such challenging markets cannot afford to suffer from the production losses caused by unexpected and unplanned equipment failures, or from long and inefficient turnarounds and shutdowns of their critical equipment.

In this scenario, companies all over the world are being called to pursue a vision of perfection in all the processes that form their value-creation chains, and embark on a journey to manufacturing excellence where maintenance becomes a strategic business process.

From their traditional reactive repair culture of fixing things after they break, over the years, maintenance has shifted to a more pivotal role within organizations, and nowadays it is widely recognized as a pillar of manufacturing excellence. Those increasingly tighter markets have brought about this shift for maintenance, and upper management’s attention has recently turned to answer the question how do we capture the full value that maintenance can provide to our organization? Indeed, the development of maintenance management now goes hand in hand with the widely practiced and well-established tools and techniques that improve the performance of the core production processes.

I have seen this shift occurring in more and more companies. Maintenance – once a disorganized, reactive, and a mere cost adding function in many factories – is taking center stage as the newly-discovered target of continuous improvement and transformational initiatives focused on eliminating equipment failures and maximizing productivity. In very few companies that my work brings me to, I observe excellent or near perfect levels of maintenance management. But despite some encouraging movements and success stories here and there, star performers in maintenance are still too few, and I still see most maintenance struggling a great deal to overcome their difficulties to replace old practices with better and improved ones. Typically, a repair culture still prevails, and failure root-cause analysis is either incomplete or not done at all. Preventive maintenance is ineffective, overdone, costly, poorly executed, or simply inexistent. Maintenance work standards are inadequate, not enforced or do not exist, and the knowledge and skills of maintenance technicians and equipment operators are insufficient.

We have learned that the best-performing manufacturing companies put maintenance at the heart of their continuous improvement processes. They foster close cooperation and mutual support between maintenance technicians and production operators, and they integrate operator care activities into the standard operating procedures, enforcing the compliance with those standards religiously amongst the operators. Maintenance tasks are standardized with equal structure and rigor. Skills and knowledge are promoted amongst the equipment operators and maintenance technicians to maximize overall work performance and efficiency. 5S is exemplary in all areas, and viewed by everyone as a foundation of excellent performance.

The best companies treat equipment failures with discipline and structure, and see them as opportunities to improve their maintenance management system or the equipment itself. They conduct root cause analysis in a holistic and systemic way, improving the maintenance processes, the equipment design, the operator’s standard operating procedures, maintenance standards and maintenance plans in order to avoid reoccurrence.

The best companies plan and execute maintenance tasks better, allocating resources early and more precisely, based on the criticality of equipment, risks and consequences of failures. Those companies act to introduce improvements since the early design stages of the life cycles of new equipment, in order to increase their reliability and maintainability during the operation phase. They track leading metrics of equipment performance and measure losses from ideal to attack the major causes of poor performance.

It is often challenging for executives and managers to establish a correlation between the implementation of some of those maintenance best practices and their impact on the bottom-line of the organization. For example, is 5S just a nice thing to have in the maintenance shop, and what is its real impact? How about visual management and deployment of KPIs to the factory floor? What is the impact of planning, scheduling, and regular reviews of preventive maintenance? For those managers who are still struggling to establish if that correlation really exists, it is reassuring to learn that a leading consulting firm ran a worldwide research involving dozens of manufacturing sites of different sectors, aiming to correlate various maintenance best practices with plant output. The data revealed that those sites with higher scores of maintenance practices had the highest output efficiencies.

This book is about pursuing those improvement opportunities in maintenance. It describes simple and yet powerful managerial best practices of some of the world’s best-performing manufacturing companies. Maintenance and production managers, engineers, plant managers, and executives will find in this book detailed and practical guidance on how to unleash the hidden values in their operations, creating lasting productive maintenance transformations in their organizations.

Executives and managers in various industries should seek to understand very clearly the principles of productive maintenance and work with discipline and constancy of purpose to harness their plant’s improvement power and bring maintenance management at least one or two generations ahead of where it finds itself now. I believe that better maintenance practices will not bring gains to the industrial sector alone. The whole society will benefit from a new way of thinking about maintenance, and this new way of thinking should be disseminated amply by the companies, universities and governments.

By sharing proven knowledge and tools, my intention is that this book makes a significant contribution in that direction. I encourage executives, managers and supervisors to study and practice the tools described in the following chapters with faith and enthusiasm, to powerfully reach unprecedented results and make their companies more productive and competitive.

Chicago, November 2017

Harilaus Georgius d’Philippos Xenos

Chapter 1

Overview of

equipment maintenance

1 Overview of equipment maintenance

1.1 Introduction

Although the maintenance of equipment has been a key activity across many industries, and that most companies understand its value for operational reliability and business excellence, it is still common to find some confusion and misconceptions about the principles of maintenance, as simple as they may be. These misconceptions can be very costly for companies: either from lower asset reliability or higher maintenance costs per se.

The main issue that this chapter addresses is the need for a clear and uniform understanding of the methods of maintenance and the way of thinking supporting the overarching concept of productive maintenance. This chapter will clarify key definitions; organize ideas and interrelationships of the various maintenance methods inside productive maintenance. Finally, this chapter will describe how the various elements of maintenance management work together as a system with the maintenance plan at the core.

1.2 Definition of maintenance

Maintenance is the combination of technical and administrative actions, including supervision, with the objective of retaining or restoring a component or piece of equipment to a state in which it can perform its required functions. Namely, to maintain means to do everything that is necessary to ensure that equipment continues to function according to its design, and at the required level of performance.

To that effect, maintenance exists to avoid the degradation of assets caused by their natural wear and their usage. Degradation happens in a variety of ways and degrees: from bad external appearance, to partial or complete loss of function, production interruptions and downtime, poor quality products, safety and environmental hazards.

Maintenance typically includes activities related to failure prevention – through periodic basic care, inspections, overhauls and replacement of parts – and the treatment of failures after they have occurred: detection and repair of the failures, investigation of the root causes and taking countermeasures to block their recurrence.

Since maintenance often represents a large element in a manufacturing site, and play an important role in productivity, its impact cannot simply be overlooked. Even in companies where maintenance costs might have only a small impact on the bottom-line, maintenance can still influence overall costs by ensuring that the equipment operate reliably.

1.3 The scope of maintenance activities beyond just maintaining

Many problems still occur because some maintenance professionals do not realize what the real scope of their activities should be. In a stricter sense, maintenance activities will be limited to the return of equipment to its original condition. Nevertheless, in a broader sense, maintenance activities should also involve modifying the original condition of the equipment by introducing improvements to prevent the occurrence or recurrence of failures, to reduce costs, or increase OEE and productivity. Only maintaining conditions is often insufficient for business excellence. Therefore, improvements should also be part of the maintenance work.

Improvements generally modify an equipment’s original operating conditions, its performance and intrinsic reliability, by incorporating modifications or changes to their original design or configuration. Improvements may also bring specific technical and managerial best practices that result in the modification of existing standards and procedures.

Finally, major modifications that aim to largely increase production capacity are outside the immediate scope of maintenance activities. Nonetheless, depending on their complexity and the technical resources required, existing maintenance teams within the companies, often in cooperation with engineering, may plan and implement such major modifications.

In synthesis, we may consider that the purpose of maintenance is to not only maintain or restore the physical condition of the equipment, but primarily to maintain and improve its functional capabilities. Namely, in addition to keeping what the equipment is physically, it is necessary to maintain what it can do functionally. In fact, maintaining the physical condition of the equipment has the ultimate objective of maintaining its functional capacity, as well as product quality, safety and environmental integrity.

To facilitate the understanding of this concept, let us illustrate it through a practical example.

Example 1.1

In a beverage factory, one of the critical processes is the filling of cans and bottles. If a particular line is designed for a capacity of 120,000 cans per hour, in principle, maintenance must work to maintain the capacity of the equipment steady. Thus, a wide variety of maintenance services will be required. For example, periodic cleaning, lubrication of bearings, alignments, tightening; replacement of parts with limited service life, vibration control, and overhaul of components that wear out over time. All these tasks aim to maintain certain physical conditions that are indispensable for the maintenance of the performance expected from the equipment, e.g. its functional capacity.

In addition to ensuring the good performance of equipment, maintenance is important to ensure the quality of the product during processing. In this case, the physical conditions of the filling machine must include the correct cleaning, filling and labelling of the cans, and that damage to the cans will not occur during conveyor transportation, capping, pasteurizing, packaging and stacking processes.

Eventual failures will certainly reduce the functional capacity of the line, either by a slower pace of production, the generation of defective products or by frequent interruptions and downtimes. Therefore, maintenance activities affect the reliability of a piece of equipment and the Overall Equipment Efficiency (OEE) of the entire line.

Concurrently with the effects on OEE, improvements also aim to increase productivity by reducing maintenance costs. For example, relocating gearboxes of the can conveyors may be necessary to reduce maintenance time, or redesign some parts to make them stronger.

1.4 Productive maintenance

As an overarching concept, productive maintenance can be understood as the optimum application of various maintenance methods to optimize the economic factors of production, ensuring the best use and high productivity of the equipment with the lowest overall cost.

Productive maintenance includes activities along all stages of the life cycle of the equipment, from their early specification to their decommissioning, and considers the maintenance costs and productivity of the equipment throughout its entire life cycle.

Productive maintenance also follows the principle that the actions of the maintenance department alone will be insufficient to ensure the performance of the equipment, so it seeks the close cooperation with other departments of the company, mainly with production and engineering. After all, the design of the equipment and the way it is operated by production also directly influence its maintenance costs.

In summary, the fundamental goal of productive maintenance is not simply to avoid equipment failures, but also to apply the best combination of maintenance methods throughout its life cycle to maximize productivity, resulting in a high economic result for the whole company.

Next, let us have a look at the various maintenance methods under productive maintenance.

1.4.1 Corrective maintenance

As a method, corrective maintenance is the choice to fix a component or piece of equipment after the failure has occurred. In principle, the choice for this method of maintenance should consider risks and economic factors: what is the risk – likelihood vs. consequences – of the failure? Is it more economical to fix a failure than to take preventive actions? If so, corrective maintenance is a sound option.

From the strict point of view of maintenance costs, corrective maintenance is cheaper than the prevention of failures. On the other hand, from a risk point of view, it can also create safety and environmental hazards, production interruptions and downtimes. Therefore, consider thoroughly the criticality of equipment to the production process, and the consequences if it fails. If there are preventive actions that can avoid the occurrence of equipment failures, are these actions technically and economically feasible? If there are no viable and cost-effective preventive actions, then how do we mitigate the consequences of the failure while it may still happen.

Furthermore, to choose corrective maintenance it is still necessary to organize resources – spare parts, labor and tooling – in order to act quickly and minimize the impacts of the failure. For example, have in stock pre-assembled components or kits ready for quick replacements.

It is also important to note that, although corrective maintenance may have been chosen for its economical advantages, we cannot simply be conformed with the occurrence of failures as something that is expected and, therefore, acceptable. A key continuous improvement mindset, even in the case of choosing to fix, is to strive to precisely identify the root causes of the failure and block them in order to prevent its recurrence.

1.4.2 Preventive maintenance

Prevention should be the main concern of maintenance in any company, and an effective preventive maintenance plan should be at the heart of productive maintenance, thus, an optimized set of effective time- and condition-based activities.

Compared to corrective maintenance – from the maintenance cost point of view only – preventive maintenance can be more expensive, because parts may have to be replaced, and components may have to be overhauled before the end of their useful lives.

On the other hand, through effective preventive maintenance the frequency of occurrence of failures and unexpected interruptions of production will be very rare, and the availability of equipment higher. If we consider the total cost, preventive maintenance often ends up being cheaper than corrective maintenance.

A common misconception of preventive maintenance is to associate it only with the periodic, time-based interventions for the replacement of parts and overhaul of components, when preventive maintenance also actually includes on-condition, or predictive interventions. Still unbeknownst to many people in maintenance, parts and components are up to seven times more likely to fail prematurely sometime in their early life, typically originating from problems of manufacture, assemble or installation.

However, by being overcautious and assuming that items will always increasingly fail as they age, meaning increasing probabilities of failure over time, companies simply resort to only time-based interventions for all of their critical or even less critical equipment. This might be causing more harm by actually inducing errors and introducing causes of failure at each intervention, due to the more frequent disassembling and reassembling, removal and reinstallations, switching equipment off and on again, and so on.

From a compliance point of view, most companies already have some sort of preventive maintenance plan created. However, what we typically see on the factory floor of many of them is maintenance trapped in a reactive cycle of failure repairs, barely allocating time for preventive maintenance. This time usually ends up mostly consumed by unanticipated failures and a backlog of work orders that are difficult to manage.

The other extreme is to see maintenance burdened by over maintaining the equipment, with too frequent or too many interventions. A common myth is that adding more time- or condition-based preventive maintenance is safer, when, in reality, maintenance may be over servicing the equipment with no added benefits, just the risk of inducing failures and increasing costs.

The key to effective prevention is to create an optimized plan with the minimally necessary time- and condition-based activities that substantively contribute to reliability. Then, execute this plan with a high degree of compliance, and seek to optimize it continually through regular feedbacks from the technicians on the factory floor. The plan should never be static: review activities and intervals periodically, and look for opportunities to improve it.

1.4.3 Predictive maintenance – Condition-based interventions

As a subset of preventive maintenance, predictive maintenance allows optimizing the time of replacement of parts and overhaul of components, and extends maintenance intervals, because it allows predicting when the part or component will be close to the end of its expected useful life. Instead of time-based interventions regardless of condition, disassemble and removals of parts and components under predictive maintenance will happen based on the condition of the item.

The technology available today has enabled the development of dozens of predictive maintenance techniques and hand-held instruments, which have become simpler, accessible to more professionals, and fully connected with computerized maintenance management systems. Predictive maintenance has become is a fairly simple and effective maintenance method that brings good results.

For example, by monitoring the vibration trends of the equipment, it is possible to predict when to change the bearings. It is also possible to predict the time to overhaul mechanical components by analyzing the lubricating oil.

1.4.4 Improvement of equipment

Another key method of maintenance is the improvement or kaizen – of the equipment. The Japanese word kaizen means to make improvements. The use of this word implies the gradual and continuous nature of the improvements. In the context of maintenance, kaizen applied to the equipment means improving them continuously beyond their original specifications.

For example, instead of simply returning the equipment to their original condition after a failure occurs, thoroughly investigate the root causes and improve their design, operating and maintenance standards. This is one of the weak points of maintenance. In many companies, maintenance means only checking if all is working fine and repairing what has broken – removing the symptom of the failure and returning the equipment to production, until it fails again.

We must always set OEE-based improvement goals for the equipment, even if failures did not occur. For example, increased life of equipment; reduction in the occurrence of failures; reduction of the time for maintenance activities; reduction of the cost of spare parts, among others

Improvement activities entail specific technical and managerial actions that result in the modification of existing standards and procedures.

1.4.5 Maintenance prevention

We must also practice maintenance prevention combined with the other methods of maintenance. Maintenance prevention consists of activities in cooperation with the engineers and manufacturers since the early phases of design and build of the equipment, in order to reduce the maintenance load required during its operation – improve maintainability.

For example, if a power generator was incorrectly specified during the design phase of an industrial plant, maintenance activities alone during the operation phase may be insufficient to ensure the reliability of the plant. Of course, the solution to this problem goes beyond the reach of routine maintenance activities, and only improvement activities will be able to improve the reliability of the power generator. For example, by installing a larger generator with more capacity.

An undesirable option would be to reduce the power demand for the generator, thus, allow it to operate within its original specification limits. In practice, having equipment that is capable of meeting production expectations, rather than adapting production to equipment limitations, is a better practice.

In his book, Design and Manage to Life Cycle Cost (1978),