Maintenance, Replacement, and Reliability

Theory and Applications

Andrew K. S. Jardine, Albert H. C. Tsang

• Publisher: CRC Press
• Year: 2021
• ISBN:
  9780429664465
• Edition: 3
• Topic: Tecnología e ingeniería
• Subtopic: Ingeniería general

Since the publication of the second edition in 2013, there has been an increasing interest in asset management globally, as evidenced by a series of international standards on asset management systems, to achieve excellence in asset management. This cannot be achieved without high-quality data and the tools for data interpretation. The importance of such requirements is widely recognized by industry.

The third edition of this textbook focuses on tools for physical asset management decisions that are data driven. It also uses a theoretical foundation to the tools (mathematical models) that can be used to optimize a variety of key maintenance/replacement/reliability decisions. Problem sets with answers are provided at the end of each chapter. Also available is an extensive set of PowerPoint slides and a solutions manual upon request with qualified textbook adoptions.

This new edition can be used in undergraduate or post-graduate courses on physical asset management.

1 Introduction

DOI: 10.1201/9780429021565-1

1.1 From Maintenance Management to Physical Asset Management

According to the classic view, the role of maintenance is to fix broken items. Taking such a narrow perspective, maintenance activities will be confined to the reactive tasks of repair actions or item replacement triggered by failures. Thus, this approach is known as reactive maintenance, breakdown maintenance, or corrective maintenance. A more recent view of maintenance is defined by Geraerds (1985) as “all activities aimed at keeping an item in, or restoring it to, the physical state considered necessary for the fulfillment of its production function.” Obviously, the scope of this enlarged view also includes proactive tasks, such as routine servicing and periodic inspection, preventive replacement, and condition monitoring. Depending on the deployment of responsibilities within the organization, these maintenance tasks may be shared by several departments. For instance, in an organization practicing total productive maintenance (TPM), the routine servicing and periodic inspection of equipment are handled by the operating personnel, whereas overhauls and major repairs are done by the maintenance department (Nakajima 1988). TPM will be discussed in more detail in Section 1.5.

If the strategic dimension of maintenance is also taken into account, it should cover those decisions taken to shape the future maintenance requirements of the organization. Equipment replacement decisions and design modifications to enhance equipment reliability and maintainability are examples of these activities. The Maintenance Engineering Society of Australia (MESA) recognizes this broader perspective of maintenance and defines the function as “the engineering decisions and associated actions necessary and sufficient for the optimization of specified capability.” Capability, in the MESA definition, is the ability to perform a specific action within a range of performance levels. The characteristics of capability include function, capacity, rate, quality, responsiveness, and degradation. The scope of maintenance management, therefore, should cover every stage in the life cycle of technical systems (plant, machinery, equipment, and facilities): specification, acquisition, planning, operation, performance evaluation, improvement, and disposal (Murray et al. 1996). When perceived in this wider context, the maintenance function is also known as physical asset management (PAM).

1.2 Challenges of PAM

The business imperative for organizations seeking to achieve performance excellence demands that these organizations continuously enhance their capability to create value for customers and improve the cost-effectiveness of their operations. PAM, an important support function in businesses with significant investments in plants and machinery, plays an important role in meeting this tall order.

The performance demanded of PAM has become more challenging as a result of the four developments discussed below.

1.2.1 Emerging Trends of Operation Strategies

The conventional wisdom of embracing the concept of economy of scale is losing followers. An increasing number of organizations have switched to lean manufacturing, just-in-time production, and six-sigma programs. These trends highlight a shift of emphasis from volume to quick response, elimination of waste, reduced stock holding, and defect prevention. With the elimination of buffers in such demanding environments, breakdowns, speed loss, and erratic process yields will create immediate problems in the timely supply of products and services to customers. Installation of the right equipment and facilities, optimization of the maintenance of these assets, and the effective deployment of staff to perform maintenance activities are crucial factors to support these operation strategies.

1.2.2 Toughening Societal Expectations

There is widespread acceptance, especially in the developed countries, of the need to preserve essential services, protect the environment, and safeguard people’s safety and health. As a result, a wide range of regulations have been enacted in these countries to control industrial pollution and prevent accidents in the workplace. Scrap, defects, and inefficient use of materials and energy are sources of pollution. They are often the result of operating plant and facilities under less than optimal conditions. Breakdowns of mission-critical equipment interrupt production. In chemical production processes, a common cause of pollution is the waste material produced during the start-up period after production interruptions. Apart from producing waste material, catastrophic failures of operating plants and machinery are also a major cause of outages of basic services, industrial accidents, and health hazards. Keeping facilities in optimal condition and preventing critical failures are effective means of managing the risks of service interruptions, pollution, and industrial accidents. These are part of the core functions of PAM.

1.2.3 Technological Changes

Technology has always been a major driver of change in diverse fields. It has been changing at a breathtaking rate in recent decades, with no signs of slowing down in the foreseeable future. Maintenance is inevitably under the influence of rapid technological changes. Nondestructive testing, transducers, vibration measurement, thermography, ferrography, and spectroscopy make it possible to perform nonintrusive inspection. By applying these technologies, the condition of equipment can be monitored continuously or intermittently while it is in operation. This has given birth to condition-based maintenance (CBM), an alternative to the classic time-driven approach to preventive maintenance.

Power electronics, programmable logic controllers, computer controls, transponders, and telecommunications systems are used to substitute electromechanical systems, producing the benefits of improved reliability and flexibility, small size, light weight, and low cost. Fly-by-wire technology, utilizing software-controlled electronic systems, has become a design standard for the current generation of aircraft. Flexible manufacturing cells and computer-integrated manufacturing systems are gaining acceptance in the manufacturing industry. In some of the major cities, contactless smartcards have gained acceptance as a convenient means of making payments. In the electric utility industry, automation systems are available to remotely identify and deal with faults in the transmission and distribution network. Radio-frequency identification (RFID) technology can be deployed to track mobile assets such as vehicles. Data transmitted to RFID tags from sensors embedded in mission-critical assets can be used for health monitoring and prognosis.

The deployment of these new technologies is instrumental to enhancing system availability, improving cost-effectiveness, and delivering better or innovative services to customers. The move presents new challenges to asset management. New knowledge has to be acquired to specify and design these new technology-enabled systems. New capabilities have to be developed to commission, operate, and maintain such new systems. During the phase-in period, interfacing old and new plants and equipment is another challenge to be handled by the PAM function (Tsang 2002).

1.2.4 Increased Emphasis on Sustainability

Sustainability is a concept that demands all developments to be sustainable in the sense that they “meet the needs of the present without compromising the ability of future generations to meet their own needs” (Brundtland Commission Report 1987). There are three pillars of sustainability representing environmental, societal, and economic demands; these are also known as the triple bottom lines. Sustainability is gaining importance in today’s business environment. In response to this business imperative, companies realize that solely focusing on operational excellence will no longer be sufficient to stay competitive; they need to address sustainability demands as business-critical issues. Regulations, social awareness and responsibility, standards, and corporate citizenship are some of the many forces that are pushing companies to become more sustainable. In the manufacturing sector, maintenance is becoming a crucial competency in realizing a sustainable society, especially when considering the entire life cycle of products and assets. As a result, the role of PAM has evolved. Companies successful in their sustainability efforts adopt a holistic approach to managing their assets, in which PAM is not addressed in isolation, but in the context of the business supported by these assets. Total cost of ownership, life cycle performance, energy consumption, asset disposal, and safety are all parameters that can be effectively optimized by the application of appropriate methodologies of and tools for PAM. For example, the right maintenance approach can add value to the organization by enabling maintenance decision-makers to plan interventions that consider sustainability demands. Consequently, the integration of factors related to sustainability is increasingly emphasized in PAM. As such, “sustainable” is enshrined as one of the key principles and attributes of successful asset management in ISO 55001, a framework for the optimized management of physical assets, which will be introduced in Section 1.4.

1.3 Improving PAM

To meet the challenges identified in Section 1.2, organizations need to focus on improving the performance of their physical assets. This can be accomplished by having a clear strategy, the right people and systems, appropriate tactics, and controlled work through planning and scheduling, maintenance optimization, and process reengineering.

1.3.1 Maintenance Excellence

A survey conducted by the Plant Engineering and Maintenance magazine (Robertson and Jones 2004) indicated that maintenance budgets ranged from 2% to 90% of the total plant operating budget, with the average being 20.8%. It can be reasoned that operations and maintenance represent a major cost item in equipment-intensive industrial operations. These operations can achieve significant savings in operations and maintenance costs by making the right and opportune maintenance decisions. Unfortunately, maintenance is often the business process that has not been optimized. Instead of being a liability of business operations, achieving excellence in maintenance will pay huge dividends through reduced w...