Integrity Rate Of Equipment
The most used of these indicators, but its contribution to management is limited. The so-called intact rate refers to the ratio of intact equipment to the total number of equipment during the inspection period (equipment intact rate=number of intact equipment/total number of equipment). The indicators of many factories can reach more than 95%. The reason is very simple. At the moment of inspection, if the equipment is in operation and there is no failure, it is considered to be in good condition, so this indicator is easy to achieve. It can easily mean that there is not much room for improvement, which means that there is nothing to improve, which means that it is difficult to improve. For this reason, many companies propose to modify the definition of this indicator, for example, propose to check three times on the 8th, 18th, and 28th of each month, and take the average of the intact rate as the intact rate of this month. This is certainly better than checking once, but it’s still a good rate reflected in dots. Later, it was proposed that the hours of the intact table be compared with the hours of the calendar table, and the hours of the intact table are equal to the hours of the calendar table minus the total table hours of faults and repairs. This indicator is much more realistic. Of course, there is an increase in the statistical workload and the authenticity of the statistics, and the debate on whether to deduct when encountering preventive maintenance stations. Whether the indicator of intact rate can effectively reflect the status of equipment management depends on how it is applied.
Failure Rate Of Equipment
This indicator is easy to be confused, and there are two definitions: 1. If it is the failure frequency, it is the ratio of the number of failures to the actual start-up of the equipment (failure frequency = number of failure shutdowns / actual number of equipment startups); 2. If it is the failure shutdown rate, It is the ratio of the downtime of the fault to the actual start-up of the equipment plus the time of the downtime of the fault (the downtime rate = the downtime of the fault/(the actual start-up time of the equipment + the time of the downtime of the fault)) Obviously, the downtime rate of the fault can be compared It truly reflects the status of the equipment.
Availability Rate Of Equipment
It is widely used in western countries, but in my country, there are two differences between planned time utilization rate (planned time utilization rate = actual working time/planned working time) and calendar time utilization rate (calendar time utilization rate = actual working time/calendar time) formulation. Availability as defined in the West is actually calendar time utilization by definition. The calendar time utilization reflects the full utilization of the equipment, that is to say, even if the equipment is operated in a single shift, we calculate the calendar time according to 24 hours. Because no matter whether the factory uses this equipment or not, it will consume the assets of the enterprise in the form of depreciation. The planned time utilization reflects the planned utilization of the equipment. If it is operated in a single shift, the planned time is 8 hours.
Mean Time Between Failures (MTBF) Of Equipment
Another formulation is called the average trouble-free working time “the mean interval between equipment failures = the total time of trouble-free operation in the statistical base period / the number of failures”. Complementary to the downtime rate, it reflects the frequency of failures, that is, the health of the equipment. One of the two indicators is enough, and there is no need to use related indicators to measure a content. Another indicator that reflects maintenance efficiency is mean time to repair (MTTR) (average time to repair = total time spent on maintenance in the statistical base period/number of maintenance), which measures the improvement of maintenance work efficiency. With the advancement of equipment technology, its complexity, maintenance difficulty, fault location, average technical quality of maintenance technicians and equipment age, it is difficult to have a definite value for maintenance time, but we can measure its average status and progress based on this.
Overall Equipment Effectiveness (OEE)
An indicator that reflects equipment efficiency more comprehensively, OEE is the product of the time operating rate, performance operating rate and qualified product rate. Just like a person, the time activation rate represents the attendance rate, the performance activation rate represents whether to work hard after going to work, and to exert due efficiency, and the qualified product rate represents the effectiveness of the work, whether frequent mistakes are made, and whether the task can be completed with quality and quantity. The simple OEE formula is overall equipment efficiency OEE=qualified product output/theoretical output of planned working hours.
Total Effective Productivity TEEP
The formula that best reflects equipment efficiency is not OEE. Total Effective Productivity TEEP=qualified product output/theoretical output of calendar time, this indicator reflects the system management defects of equipment, including upstream and downstream impacts, market and order impacts, unbalanced equipment capacity, unreasonable planning and scheduling, etc. come out. This indicator is generally very low, not good-looking, but very real.
Maintenance And Management Of Equipment
There are also related indicators. Such as the one-time qualified rate of overhaul quality, repair rate and maintenance cost rate, etc.
1. The one-time pass rate of the overhaul quality is measured by the ratio of the number of times the overhauled equipment meets the product qualification standard for one trial operation to the number of overhauls. Whether the factory adopts this indicator as the performance indicator of the maintenance team can be studied and deliberated.
2. The repair rate is the ratio of the total number of repairs after equipment repairs to the total number of repairs. This is a true reflection of the quality of maintenance.
3. There are many definitions and algorithms of maintenance cost ratio, one is the ratio of annual maintenance cost to annual output value, the other is the ratio of annual maintenance cost to the total original value of assets in the year, and the other is the ratio of annual maintenance cost to total assets in the year The ratio of replacement cost is the ratio of annual maintenance cost to the total net asset value of the year, and the last is the ratio of annual maintenance cost to total production cost of the year. I think the last algorithm is more reliable. Even so, the magnitude of the maintenance cost rate cannot explain the problem. Because equipment maintenance is an input, which creates value and output. Insufficient investment and prominent production loss will affect output. Of course, too much investment is not ideal. It is called overmaintenance, which is a waste. Appropriate input is ideal. Therefore, the factory should explore and study the optimal investment ratio. High production costs mean more orders and more tasks, and the load on the equipment increases, and the demand for maintenance also increases. Investing in an appropriate ratio is the goal that the factory should strive to pursue. If you have this baseline, the farther you deviate from this metric, the less ideal it is.
Spare Parts Management Of Equipment
There are also many indicators, and the turnover rate of spare parts inventory (the turnover rate of spare parts inventory = monthly consumption of spare parts costs / monthly average spare parts inventory funds) is a more representative indicator. It reflects the mobility of spare parts. If a large amount of inventory funds are backlogged, it will be reflected in the turnover rate. What also reflects spare parts management is the ratio of spare parts funds, that is, the ratio of all spare parts funds to the total original value of the enterprise’s equipment. The value of this value varies depending on whether the factory is in a central city, whether the equipment is imported, and the impact of equipment downtime. If the daily loss of equipment downtime is as high as tens of millions of yuan, or the failure causes serious environmental pollution and personal safety hazards, and the supply cycle of spare parts is longer, the inventory of spare parts will be higher. Otherwise, the funding rate of spare parts should be as high as possible. reduce. There is an indicator that is not noticed by people, but it is very important in contemporary maintenance management, that is, maintenance training time intensity (maintenance training time intensity = maintenance training hours/maintenance man-hours). Training includes professional knowledge of equipment structure, maintenance technology, professionalism and maintenance management etc. This indicator reflects the importance and investment intensity of enterprises in improving the quality of maintenance personnel, and also indirectly reflects the level of maintenance technical capabilities.
Post time: Aug-17-2023