Factors Increasing the Importance of Preventive Maintenance in Manufacturing
Chapter 4: Factors That Increase the Importance of Preventive Maintenance
As explained previously, to understand the importance of productive maintenance in a manufacturing industry, it was initially decided to segment based on the structure of the process flow. However, the previous chapter revealed that this type of classification was insufficient.
Therefore, visits to several manufacturing companies indicated the need to consider new factors that determine the importance of maintenance.
4.1 Research Field
Before visiting the industries, it was decided to create an instrument to provide a reliable diagnosis on different aspects within the company. Initially, the basis of the questions in the questionnaire was established according to the criteria of different quality awards employed for qualifying businesses. The criteria and standards of the following awards were compared:
- ISO 9001:2000
- National Quality Award
- Shingo Model
- Deming Prize
- Malcolm Baldrige Award
The summary of the criteria is in Table 4.1 in Appendix F.
Once the different criteria were known, and taking into account the department evaluation, a questionnaire consisting of 33 open questions was developed (see Appendix G).
Subsequently, a new questionnaire was developed, based on some of the questions from the first questionnaire and increasing the number of others that help analyze the maintenance area in a deeper way.
This new questionnaire was developed using the Likert scale. This scale was chosen because it is simple yet meaningful for carrying out surveys or questionnaires where the answers are given gradually, using a 5-grade scale for qualification.
This new questionnaire aims to determine, through the opinion of maintenance personnel, the level of equipment efficiency, the degree of staff knowledge in activities related to their area, and the performance of the same. This questionnaire is in Appendix H.
After analyzing the results and observations taken at each company, new factors that influence the importance of maintenance in industries were identified.
Many of these factors were repeatedly observed in different industries, so it was decided to study their effect on the study area.
These factors are summarized in Figure 4.1 and described below.
Figure 4.1: Factors Influencing the Importance of Preventive Maintenance
(Insert Figure 4.1 here, depicting factors like Maintenance Resources (Human & Physical), Process Flow, Production Volume, Product Features, Organizational Culture, Client Complaint Policy, Training, Equipment State, Workshops, Quality, Safety, Delivery Time, Plant Capacity, Team Seniority, etc.)
With the results obtained from some companies, it was concluded that these are the factors affecting the importance of maintenance (some more so than others). The following explains the effect of each of these factors on maintenance.
4.2 Effect of the Customer on Maintenance
A critical element for any company or business today is the customer. If customers are not satisfied, they will not return to buy again or recommend the products or services to others. In fact, a single dissatisfied customer can have a potentially high negative impact on an organization. Customer satisfaction is definitely the most important component of the ongoing success of any business.
It is necessary to establish a good customer-supplier relationship that has continuous communication, allowing the company to know exactly what the customer wants, both in terms of the product and the organization itself.
The production area plays an important role, but this area could not operate at maximum efficiency if there are problems with the machinery and equipment. Therefore, the qualities that the client is seeking are related to various maintenance tasks.
If there is good maintenance management and good compliance with this activity, then the company can commit to:
- Maintain the desired quality. By monitoring equipment and performing preventive maintenance, it ensures that the equipment will not deviate from the predetermined specifications and tolerances. The product will then be released with the quality implemented by the client.
- Compliance with the delivery time. By knowing the capacity of the equipment in good condition, it is possible to meet the set delivery times, eliminating customer discomfort due to delays, or possibly eliminating high costs for stopping their production line due to lack of raw material.
We know that today, losing or having a dissatisfied customer represents large losses for the company, which may be reflected in lower demand, downsizing, or even its disappearance.
The high costs for delays, returns, rework, and waste are the cause of mismanagement of maintenance. Customers are becoming more stringent in their requests every day, and all this requires suppliers to have a good maintenance system to avoid any of these problems and to ensure their place in the market.
4.3 Effect of Production Volume on Maintenance
This factor has a close relationship with the client; it is accusing a certain amount of product in a given period. In many cases, the sales department makes contracts for large orders, i.e., it exceeds the level of products that the company can produce. In most cases, this is done in accordance with the production department to determine whether such an order can be fulfilled.
Unfortunately, in the estimation of the capacity of equipment, machinery, and staff, the time required to perform preventive maintenance tasks is not taken into account. The time for this activity is considered production time; otherwise, it will not be sufficient to cover the promised sale.
When this type of situation occurs, the equipment is severely affected, and if in the future there are problems with failures and stoppages, the maintenance area manager will be held responsible.
Therefore, when making an estimate of the plant’s capacity to take new and larger orders, both the production area and the maintenance area should be taken into account.
During site visits, it was found that companies that have fully implemented a maintenance management system, in this case TPM, had merged the maintenance area with the production area, and there is a single management for these two functions. This measure would eliminate problems between staff because they have the same goal.
4.4 Effect of Organizational Culture on Maintenance
A very important aspect that largely determines the freedom or limitation of the activities of any area is the organizational culture.
Depending on the policies and mindset of the administrators, changes to any department will be positive or negative, and depending on their priorities, the importance given to maintenance will vary.
If the priority of management is to have high rates of efficiency in the production area, access to machines for maintenance personnel will be restricted.
If, in the same way, they also care about the overall productivity of the plant, obviously including maintenance, and they do not have access to equipment, they will seek to do any work or tasks, whether or not it really helps the equipment to continue working with the best quality and speed.
Likewise, if the mentality of the employees is to produce more to obtain productivity bonuses, they will care less about the state of the machine, demanding more than its ability to give.
If senior managers are not convinced that maintenance is not only necessary but is the starting point for greater productivity and that investment has many advantages, then high costs, common faults, and unwanted stoppages will persist.
4.5 Effects of Human Resources on Maintenance
The causes of defects and faults are many, and these are divided, according to Paez (1973), into three areas: condition of equipment, conditions of the area, and conditions of operators and staff.
As for the negative effects that staff may cause, they are due to:
- They make mistakes when operating.
- They do not perform regular check-ups (they do not know how).
- When it comes to equipment, only a few operators know when, how, and where it should be oiled.
- They do not know how to replace parts and make accurate checks.
- They always call maintenance for any negligible failure.
- They do not see defects as their problems but as maintenance problems.
- Their instruments and methods of measurement are inadequate.
And as for the maintenance staff, many lack training, knowledge of procedures and methodologies, and they always work individualistically.
Depending on the nature of the interest of the team members, they will respond with enthusiasm or resentment, participation or apathy, innovation or unwillingness, commitment or resistance, decision or hesitation.
Human resources are an important factor for the continuous flow of work and increasing plant productivity.
4.6 Effects of Physical Resources on Maintenance
Physical resources are the basic elements of concern for the maintenance area; therefore, it is a factor that, by its nature, matters to its administration. The degree of maintenance will depend on the current state of the equipment, as well as its age and how it is used.
4.6.1 Current Status of the Equipment
Most companies lack a production system for maintenance management. It is normal to see equipment being used beyond its capacity, causing damage, more rapid deterioration, loss of product quality, and constant faults over time.
If the equipment is not subject to periodic maintenance, as set out by the machinery supplier, then the company must be aware of the possible consequences of loss of equipment status.
When setting pre-planned work orders according to vendor specifications, and these are carried out, a considerable decrease in the damages previously discussed is ensured.
Therefore, preventive maintenance also depends on the current state of machinery and equipment because, based on this, you know its current lifetime, the load it can be subjected to, and the quality with which it can meet the established specifications. In some cases, it may be possible to extend its life and improve the quality obtained from each piece of equipment.
4.6.2 Age of the Equipment
Another important factor is the age of the equipment because, as in the previous point, knowing it will allow you to identify the requirements that can be ordered in terms of quality and capacity.
Many companies are working with equipment that exceeds the lifetime set in advance by the suppliers. This is due to the high costs involved in acquiring new equipment, training personnel who will use it, and the changes that must be made to cover this capacity gap.
If investment is not necessary to acquire new production elements, then the maintenance department should focus on existing resources, making them work as best as possible.
4.6.3 Use
If equipment is used at maximum capacity levels for efficiency and utilization as demanded by the production area, then the time these teams are free to work on them, giving them the necessary maintenance, is sometimes reduced or eliminated.
Therefore, it is necessary to establish certain standards to try to slow down the workload of the equipment to provide periodic maintenance. This point is related to demand and production volume.
It should also be taken into consideration when the company has a classification of equipment depending on its importance in the manufacturing process. For example, according to Dounce (2000), equipment can be classified as vital, normal, or trivial. Another classification used by the companies visited is named as bottlenecks and non-bottlenecks.
In either case, some teams stand out for their importance, and these should be handled with utmost care and diligence.
4.7 Effects of Process Flow on Maintenance
As explained in Chapter 1, the process flow that characterizes the company is important due to the costs that failures or stoppages represent and the consequences, which vary depending on each structure.
It is more expensive to have a stoppage or failure of a machine that is in a continuous flow line due to the losses it represents, as they stop the entire line, causing downtime and idle time for workers.
And if this is a just-in-time system, it may cause delays in client lines, meaning large fines and losses for the company.
While in workshop flows, having a breakdown or stoppage represents various costs, but not as high as in the case of continuous flow because the processes are independent, although to a lesser degree, it also has consequences for the cycle time.
4.8 Effects of Product Characteristics on Maintenance
Depending on what the product is used for once completed, the importance given to it during the manufacturing process will vary. There are many features depending on the type of product being manufactured, such as safety, entertainment, comfort, strength, personal care, consumer, etc.
In the case of safety products, maintaining the equipment should be a high priority due to the demanding standards and characteristics required of the product.
If this is a product in which someone’s life is at stake, failures must be zero. In this case, most companies work under zero defects, zero failures philosophies. This requires having a highly efficient maintenance management system so that the percentage of corrective maintenance is almost zero, and the company works almost 100% under a preventive maintenance mentality.
The product features, along with customer requirements, require the company to invest in an efficient administrative system that eliminates errors that are costly to the company.