It is used most in these indicators, but it has limited promotion to management. The so-called intact rate refers to the ratio of equipment intact rate to the total equipment during the inspection period (equipment intact rate = equipment intact rate/total equipment), and the index of many factories can reach more than 95%. There is a simple reason. At the moment of inspection, if the equipment is running and there is no fault, it means that it is in good condition, so this indicator looks good. Being good-looking means that there is not much room for improvement, that there is nothing to improve, and that it is difficult to make progress. To this end, many enterprises propose to reform the definition of this indicator, such as proposing to check it three times every month on the 8th,18th and 28th, and taking the average of its intact rate as the intact rate of this month. This is certainly better than checking once, but it still reflects the intact rate. Later, it was suggested that the intact desk hours should be compared with the calendar desk hours, and the intact desk hours should be equal to the total desk hours MINUS the faults and repairs. This indicator is too much. Of course, there is an increase in statistical workload and statistical authenticity, and there is also a debate about whether to deduct it during preventive maintenance. Whether the intact rate index can effectively reflect the equipment management situation depends on how to apply it. Different people have different opinions.
Second, the failure rate of equipment
This index is easily confused, and there are two definitions: 1. If it is fault frequency, it is the ratio of the number of faults to the actual start-up time of the equipment (fault frequency = fault stop times/actual start-up times of the equipment); 2. If it is the downtime, it is the ratio of downtime to the actual startup time of equipment plus downtime (downtime = downtime/(actual startup time of equipment+downtime)). Obviously, the outage rate can truly reflect the state of the equipment.
Third, the availability of equipment.
It is widely used in western countries, but there are two different expressions in China: planned time utilization (planned time utilization = actual working time/planned working time) and calendar time utilization (calendar time utilization = actual working time/calendar time). By definition, the availability rate defined in the west is actually the calendar time utilization rate. The utilization rate of calendar time reflects the full utilization of equipment, that is to say, even if the equipment runs in a single shift, we calculate the calendar time according to 24 hours. Because whether the factory uses this equipment or not, it consumes the assets of the enterprise in the form of depreciation. Planned time utilization rate reflects the planned utilization rate of equipment. If it is a single shift, the planned time is 8 hours.
Four, the average time between failures of equipment MTBF
Another formula is called mean time between failure (mean time between failure of equipment = total time between failures/number of failures in statistical base period). It supplements the failure rate to reflect the failure frequency, that is, the health status of the equipment. One of the two indicators is enough, and it is not necessary to measure a content with relevant indicators. Another indicator reflecting maintenance efficiency is the average maintenance time MTTR (average maintenance time = total time consumed/maintenance times in the statistical base period), which measures the improvement of maintenance efficiency. With the technical progress of equipment, its complexity, maintenance difficulty, fault location, average technical quality of maintenance technicians and service life of equipment are different, so it is difficult to have a definite value of maintenance time, but we can measure its average condition and progress accordingly.
Five, the comprehensive efficiency of equipment OEE
OEE is a comprehensive index of equipment efficiency, which is the product of time start-up rate, performance start-up rate and qualified product rate. Just like a person, the time start-up rate represents the attendance rate, the performance start-up rate represents whether you work hard and give full play to your due efficiency after going to work, and the qualified product rate represents the effectiveness of your work, whether you often make mistakes, and whether you can complete tasks with good quality and quantity. The simple OEE formula is: equipment comprehensive efficiency OEE= qualified product output/planned man-hour theoretical output.
Six, the complete effective productivity TEEP
The formula that best reflects the efficiency of equipment, not OEE. Total effective productivity TEEP= qualified product output/theoretical output of calendar time, which reflects the defects of equipment system management, including upstream and downstream influence, market and order influence, unbalanced equipment capacity, unreasonable planning and scheduling, etc. This indicator is generally low and unsightly, but it is very real.
Seven, about maintenance management.
There are related indicators. Such as the first pass rate of maintenance quality, repair rate, maintenance expense rate, etc.
1. The first pass rate of overhaul quality is measured by the ratio of the number of times that the overhaul equipment reaches the product qualification standard after a trial run to the number of overhaul times. Whether the factory adopts this index as the performance index of the maintenance team can be studied and scrutinized.
2. The repair rate is the ratio of the total number of repairs after equipment maintenance to the total number of repairs. This truly reflects the quality of maintenance.
3. There are many definitions and algorithms of maintenance expense ratio, one is the ratio of annual maintenance expense to total annual output value, the other is the ratio of annual maintenance expense to total original value of assets in that year, the third is the ratio of annual maintenance expense to total cost of asset replacement in that year, the fourth is the ratio of annual maintenance expense to total net asset value in that year, and the fifth is the ratio of annual maintenance expense to total production cost in that year. I think the last algorithm is more reliable. Even so, the value of this maintenance cost rate can't explain the problem. Because equipment maintenance is an input, and input creates value and output. Insufficient investment and prominent production losses will affect the output; Of course, too much investment is not ideal, which is called excessive maintenance and a waste. Proper investment is the best. Therefore, factories should explore and study the best investment ratio. High production cost means more orders and tasks, increased equipment load and increased maintenance demand. Appropriate investment ratio is the goal that the factory should strive to pursue. If you have this benchmark, the farther away from this indicator, the less ideal it is.
Eight, about spare parts management
There are many indicators, and the spare parts inventory turnover rate (spare parts inventory turnover rate = monthly spare parts expenses/monthly average spare parts inventory funds) is a representative indicator. It reflects the mobility of spare parts. If there is a large backlog of inventory funds, it will be reflected in the turnover rate. Spare parts management also reflects the spare parts fund rate, that is, the ratio of all spare parts funds to the total original value of enterprise equipment. This value varies with the influence of whether the factory is in the central city, whether the equipment is imported and the loss of equipment downtime. If the loss of equipment downtime is as high as tens of millions of yuan a day, or the failure causes serious harm to environmental pollution and personal safety, the spare parts supply cycle will be longer, and the spare parts inventory will be higher, otherwise the spare parts fund rate will be reduced as much as possible. In contemporary maintenance management, there is a very important indicator that people don't pay attention to, that is, the time intensity of maintenance training (maintenance training time intensity = maintenance training hours/maintenance work hours). The training content includes professional knowledge of equipment structure, maintenance technology, professionalism and maintenance management. This index reflects the importance and investment intensity of enterprises to improve the quality of maintenance personnel, and indirectly reflects the level of maintenance technical ability.