“Equipment maintenance” may be a word that cannot be heard by the general public. The production technology department of the factory is often in charge, but it is an initiative to maintain and improve the productivity of the production line. Here, we will briefly explain the outline of equipment maintenance and introduce what kind of equipment maintenance activities are available.
What is Equipment maintenance?
The definition of equipment maintenance is “activities to maintain the performance of equipment in perfect condition and contribute to normal production”. Simply put, it is an activity to maintain the performance of production equipment and produce products that do not have breakdowns or defects as planned.
* Each term in the field of equipment maintenance has an accurate definition in JIS Z8141 (Japanese Industrial Standard). If you are interested, please refer to it.
A production facility is a collective term for physical means for providing production activities. This includes machines, equipment, tools, and instruments, as well as land and buildings. On the other hand, because it is a “physical means”, “people” such as workers are not included. Equipment maintenance is also called machine maintenance, but conceptually it is almost the same.
Internal translation of equipment maintenance
Equipment maintenance is roughly divided into “maintenance activities” and “improvement activities”.
Maintenance activities are activities to maintain the performance of a production system when designing as much as possible. Usually, in the case of “equipment maintenance”, this “maintenance activity” is often referred to.
On the other hand, improvement activities are activities to repair and improve production systems with deteriorated performance. There are two types of products: “improved maintenance”, which improves and remodels existing equipment so that it is hard to break, and “maintenance prevention”, which emphasizes durability at the design stage of the equipment. This is the case when the equipment is expensive and extends life, or when remodeling or upgrading.
Internal translation of maintenance activities
There are “preventive maintenance” and “post-maintenance” in maintenance activities.
Preventive maintenance is maintenance before it breaks down. It is good to think that it is always grasped the condition of the equipment and the production line and it takes the hand before it becomes a breakdown. Alternatively, preventive maintenance includes knowing in advance the habit of equipment and production lines that cause failures.
Post-maintenance refers to the so-called “repair of a failure”. This can be considered to have a negative impact on production activities. Since a failure occurs suddenly, it is necessary to analyze the failure from a state where nothing is known when maintenance (repair) is performed after the failure. This will take time to restore equipment and production lines, and productivity will be greatly reduced. For this reason, the priority theme of modern equipment maintenance is how to reduce this post-maintenance.
Internal translation of preventive maintenance
Preventive maintenance includes regular maintenance and predictive maintenance. Usually, we combine these two to maintain equipment.
Regular maintenance is a so-called “regular maintenance” that performs preventive maintenance on a time basis. Specifically, after regular maintenance, the contents of maintenance are recorded in the “Facility Management Ledger”. If you continue to fill out the “equipment management ledger” for a while, you will understand the habit of the equipment and production line that causes the failure. If you use this, you can respond quickly in case of trouble. As it will be described later, it is a good idea to use a dedicated system to make the most of this “facility management ledger”.
Predictive maintenance constantly monitors the condition of the equipment to diagnose and maintain signs of failure before it fails. Unlike the time standard for periodic maintenance, the standard for performing maintenance is the state of the equipment. In recent years, the latest technology has rapidly automated and intelligent this predictive maintenance. Artificial intelligence and edge computing are also being used here.
Learn more about preventive and predictive maintenance.
Stratus | preventive and predictive maintenance and edge computing
Other divisions
In addition to the breakdown of conservation that we have seen so far, there is also a way to divide centralized maintenance and departmental maintenance.
Centralized maintenance is the concentration of specialized departments (with many production technology departments) for equipment maintenance operations and intensive equipment maintenance activities. By concentrating maintenance work that requires a high level of expertise in one department, it is effective in maintaining and improving equipment maintenance technology.
Departmental maintenance is a form in which equipment maintenance work is distributed by the department of equipment (there are many manufacturing departments). Because the operation department (factory) of the equipment is often geographically dispersed, it is also called regional maintenance.
If it is a small trouble, it is faster for the manufacturing department to fix it, and if the entire line must be stopped due to serious troubles, a highly specialized production technology department must respond. In other words, the cooperative relationship between the manufacturing department and the production technology department becomes important for equipment maintenance activities.
What is the overall efficiency of the equipment?
Equipment total efficiency refers to actual production efficiency, which subtracts various losses (equipment loss) from the production efficiency (expressed by takt time, working time, etc.) targeted at the time of designing a production line.
When designing a production line, production efficiency is assumed, but the reality is often lower. One of the main objectives of equipment maintenance is to bring actual production efficiency closer to the level at design time.
The breakdown of equipment loss includes “stop-loss”, “performance loss”, and “defective loss”.
- Stop loss: stop failure, setup, and adjustment, tool change, launch
- Performance loss: slipping, chocolate stop, reduction, etc.
- Defective loss: Defective, rework, etc.
Among them, “chocolate stop” is often a problem at the production line site due to the temporary suspension of equipment and production lines. It is said to stand for “stop a little”. It may also appear as a habit of equipment or production lines. The root cause is often not clear, although it is possible that the control system of the equipment or production line overflows, or the surrounding heat rises too much and the operation is unexpected.
It is also likely to occur when operating under the last-minute conditions guaranteed by the manufacturer of the equipment and production line, such as environmental conditions, time, and speed. Turning off the power of a device or production line and re-launching it may work fine, or if left unattended, it may recover automatically.
If the number of chocolate stops suddenly increases, it is basic to be vigilant, considering it a sign of some serious trouble, but there are things that can not be found immediately even if you search for the cause. In addition, the qualities of production engineers are also important in determining whether such troubles are “chocolate stops”. It is also effective to constantly monitor equipment and production lines with a camera to sense the tendency of chocolate stops.
Automatic maintenance of equipment, especially predictive maintenance
Intelligent and automatic prediction and maintenance
A specific and general method of predictive maintenance is to attach a sensor to the device and constantly detect the condition of the part. It then warns you if there is an abnormality in the detection result and encourages the replacement of the part. Edge computing is advantageous for collecting and analyzing this data and determining normal and abnormal conditions. In particular, edge AI placed on edge servers is considered effective for determining normal and abnormal conditions. The strengths of edge computing, which can be processed immediately closer to the field, come alive.
Importance and Systematization of Facility Management Ledgers
As previously mentioned, the equipment management ledger is the one to record when it broke down after the maintenance activity ends, the part of the failure, the cause of the failure, correspondence, etc. It is a very important document for equipment maintenance activities, and the latest version is always required. Document management such as version control is a specialty of information systems, so I would like to digitize and manage it with the system so that information can be shared between related departments.
Although equipment maintenance may seem sober, it is very important
Above, we introduced equipment maintenance. The activities of people who are involved in equipment maintenance such as the production technology department may seem to be “doing something in the factory” from the perspective of strangers. However, equipment maintenance plays a very important role in increasing plant productivity and maintaining production lines.
