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Maintenance

Harpreet Sharma1*, Chandan Deep Singh2 and Kanwal Jit Singh3

1Yadavindra Department of Engineering, Guru Kashi Campus, Talwandi Sabo, Punjab, India

2Department of Mechanical Engineering, Punjabi University, Patiala, India

3School of Agriculture Sciences and Engineering, Maharaja Ranjit Singh Punjab Technical University, Bathinda, India

Abstract

In order to stay competitive, it is necessary for companies to continuously increase the effectiveness and efficiency of their production processes. Production strategies such as Justin-Time and Lean Production demand high availability of production equipment in order to meet customer satisfaction. Maintenance is a critical aspect of managing assets and ensuring their optimal performance and longevity. It involves a range of activities aimed at preserving, repairing, and optimizing equipment, systems, and infrastructure to minimize downtime, increase reliability, and reduce costs. This chapter provides an overview of maintenance practices, including preventive, corrective, and predictive maintenance, as well as their benefits and challenges.

Keywords: Preventive maintenance, corrective maintenance, routine maintenance, scheduled maintenance, predictive maintenance, breakdown maintenance

1.1 Introduction and Meaning

Past and current maintenance practices in both private and government sectors would imply that maintenance is the action associated with equipment repair after it is broken. The dictionary defines maintenance as "the work of keeping something in proper condition, upkeep." This would imply that maintenance should be actions taken to prevent a device or component from failing or to repair normal equipment degradation experienced with the operation of the device to keep it in proper working order. Data obtained in many studies over the past decade indicates that most private and government facilities do not expend the necessary resources to maintain equipment in proper working order. They wait for equipment failure to occur and then take whatever actions are necessary to repair or replace the equipment. Nothing lasts forever and all equipment has a predefined life expectancy or operational life associated with it.

1.2 Need for Maintenance

The need for maintenance is based on the actual or imminent failure. Ideally, maintenance is carried out to keep equipment and systems running efficiently during at least its usual life cycle (Lai et al., 2019). As such, the practical functioning of equipment is based on time. If you want to graphically represent the failure rate of a piece of equipment in relation to time, it is probable that the graphic will take the shape of a bathtub, such as the one shown in Figure 1.1, where the Y-axis represents the failure rate and the X-axis represents time. This curve can be divided into three periods: premature death, lifecycle, and exhaustion period.

The first period, the premature death, of the curve is characterized by a high rate of failure, followed by a decreasing failure period. Most of the failures related at this time are linked to bad design, bad installation, or wrong use. The premature death period is followed by a period with a nearly constant failure rate known as the lifecycle. There are many theories about why equipment fails in this time area. Most of them agree that poor preventive maintenance has often a key role. It is also generally agreed that exceptional practices related to predictive and preventive maintenance can extend this period. The exhaustion period is characterized by an increasing rate of failure. In most cases, this period includes a regular distribution of failures during the design life but in reverse (Jian et al., 2021).

Figure 1.1 Product failure rate.

The lifecycle of most equipment needs periodic maintenance. If we use the example of a car, we could say that filters must be changed, front-end alignment must be maintained, oil change and proper lubrication are needed, and so on. In some cases, certain pieces need to be replaced, for example, the timing belt, to ensure the proper functioning of the main piece of the equipment, in this particular case, the car, once its design life has ended. Each time we do not carry out the maintenance activities planned by the designer, we shorten the operational lifecycle of the equipment.

1.3 Importance of Maintenance

Operator and Machine Safety

By performing regular preventive maintenance, you will always be assured that your equipment will operate under safe conditions, both for the machine and the operators. Possible issues can be cut off before they cause any harm, without taking any chance.

Machine Efficiency

With normal wear and tear, machines can cause lower efficiency. Proper preventive maintenance management will assure you of the optimal working conditions of the equipment and, moreover, conserve its life span.

Time Savings

Planned preventive maintenance management will reduce the actual downtime caused by the breakdown and further enhance the products in less time, thereby saving a lot of time. Preventive maintenance will consume less time than emergency repairs and replacements.

1.4 Objectives of Maintenance

Equipment is an important resource that is constantly used for adding value to products. So, it must be kept in the best operating condition. Otherwise, there will be excessive downtime and also interruption of production if it is used in a mass production line. Poor working conditions of equipment will lead to quality-related problems. Hence, it is an absolute necessity to maintain equipment in good operating conditions at an economical cost. Hence, we need an integrated approach to minimize the cost of maintenance. In certain cases, the equipment will be obsolete over a period of time. If a firm wants to be in the same business competitively, it has to decide on whether to replace the equipment or retain the old equipment by taking the cost of maintenance and operation into account (Stone et al., 2020).

1.5 The Role of the Maintenance Department

Responsibilities of a Maintenance Department

1. Engineering and execution of planned maintenance: The responsibility for the continued economical use of the equipment lies with the operating supervisor. It is, however, the responsibility of the maintenance staff, in cooperation with the operating supervisors to organize preventive maintenance schedules and improve the equipment efficiency necessary to meet the production schedule requirements.
2. Generation and distribution of power and other utilities: The power engineer is responsible for the generation and distribution of utilities like steam and compressed air in suitable quantities, as well as the purchase and distribution of electrical power, water, etc., at minimum cost.
3. Stand-by power generation: Apart from purchasing electric power from electricity board (EB), if a stand-by diesel generator is available in the factory, the maintenance staff would be responsible for operating this generator and supplying sufficient power during power outages.
4. Administrative and staffing: To handle mechanical work involved in carrying out the functions of the maintenance department, an adequate skilled labor force, provided with suitable equipment and proper supervision, is necessary. The type and size of this group are determined based on a balance between the costs of establishing and maintaining the group versus the cost of contracting for the maintenance work to outside firms, considering the factor of emergency and round-the-clock service. It is the responsibility of the head of the maintenance department to plan and coordinate work distribution among the crafts and to organize and carry out programs for the training of the supervisors and craftsmen.
5. Engineering and supervision of construction projects within the scope of the group: Maintenance engineering is a definite part of the preliminary and final design of construction projects. It is the responsibility of the maintenance group to be familiar with all the projects under consideration or execution that will eventually become a part of the plant.
6. Technical consultation: The maintenance engineer would act as a consultant to the production department in solving the mechanical problem of the equipment.
7. Plant safety activities and equipment: The provision and control of all safety equipment, their maintenance, and monitoring for the general observance of plant safety practices by all workforces in the plant, would be the responsibility of the maintenance department.
8. Plant insurance: Strategies for securing plant insurance and ensuring the preservation of all critical data and documents, as well as taking the necessary action in the event of accidents.
9. Service facilities: Engineering, administration, and maintenance of various service facilities delegated to the departments like yards, roadways, washing rooms, sewers and waste disposal sections, and employee welfare services within the budgets provided by the management.
10. Maintenance of plant and equipment records: Maintaining the property and all relevant records of all plant and equipment required for the annual accounts and audit.
11. Meticulous breakdown record-keeping for future maintenance planning: Keeping the breakdown record for each and every piece of machinery and equipment meticulously as required for future maintenance...