Over the past century, open pit mines have steadily increased their production rate by using larger equipments which require intensive capital investment. Low commodity prices have forced companies to decrease their unit cost by improving productivity. One way to improve productivity is to utilize equipment as effectively as possible. Therefore, the accurate estimation of equipment effectiveness is very important so that it can be increased. Overall Equipment Effectiveness (OEE) is a well-known measurement method, which combines availability, performance and quality, for the evaluation of equipment effectiveness in manufacturing industry.
However, there isn’t any study in literature about how to use this metric for mining equipments such as shovel, truck, drilling machine etc. This paper will discuss the application of OEE to measure effectiveness of mining equipment . It identifies causes of time losses for shovel and truck operations and introduces procedure to record time losses. The procedure to estimate OEE of shovels and trucks has also been presented via numerical example.
Introduction
All industries are dependent on their assets as well as mining companies. The increase in automation, compounded by the increase in the size and capacity of equipment over the years has drastically changed the consequences of equipment ineffectiveness. Current economic conditions, severe global competition, environmental regulations and a continually improving focus on safety are also causing mine managers to consider creative and proven methods to determine effectiveness of their equipment so they can take necessary precautions to increase the effectiveness of their equipment and to reduce the total production cost.
Mining is a very capital-intensive industry, and it is known fact that the equipment utilization and accurate estimation of this utilization are very important since mine managers want to utilize their equipment as effectively as possible to get an early return on their investments as well reducing total production cost. Many studies have been carried out on selection of mining equipments [1-5]. But there has been a little attention on the measurement of effectiveness of those equipments. Only maintenance policies have been studied and implemented in order to improve availability of these equipments [6-10]. Therefore the aim of this study is to introduce a method, which is widely accepted in manufacturing industries, used in measuring overall effectiveness of equipments known as Overall Equipment Effectiveness (OEE).
What is OEE?
OEE is a simple tool that will help manager to measure the effectiveness of their equipment. It takes the most common and important sources of productivity loss, which are called six big losses and given in Table 1. These losses are quantified as availability, performance and quality in order to estimate OEE as given in equation: OEE = Availability × Performance × Quality.
OEE for mining equipment
OEE applications in mining industry differ from manufacturing industry. Therefore, it is necessary to develop equipment’s own classification framework for the losses, which should be associated with the components of availability, performance and quality [16]. The necessary data classification to be collected will vary from equipment to equipment. In addition to that, it is more difficult to gather data for mining equipments due to following reasons:
• Mining is a serial operation of drilling-blasting, loading, hauling and dumping. Therefore, the production of equipments used in each step depends on the production of previous equipment. That means utilization of each equipment affects the others.
• The capacity of mining equipment is huge. Therefore the effect of utilization on total production is very high.
• The physical environment under which mining equipment operates is less than ideal.
• The operating environment of the mine is dynamic with many unknowns that can affect the equipment utilization drastically. In this study, OEE of shovels and trucks have been considered since they are the main equipments for the most of the Open Pit Mines.
Conclusions
Utilization of equipment can only be improved and controlled successfully if an appropriate performance measurement system is used. OEE is a known method to measure performance of production equipment in manufacturing industries and adapted for mining industry in this paper. It aims to identify unproductive time losses within the system and these time losses affect availability, performance and quality.
This paper has shown that what are the possible time losses for mining equipments, more specifically shovel and trucks, and how they can be used in the calculation of OEE. The difference between calendar time-based approach and loading time-based approach is also discussed to set benchmark for improvement. Loading time-based approach provides higher OEE values than calendar time-based approach. Therefore, it is important to declare which approach is used when one talks about OEE of any specific equipment.
The importance of proper data collecting system to estimate OEE is also emphasized. If data are not properly collected then the resulting OEE will not be meaningful. Most of the equipment producers provide data collecting system for their equipments, the manager just needs to classify them according to definitions.
Archives
Recent Posts
Categories
Calendar
Meta
Performance Measurement of Mining Equipments by Utilizing OEE
Over the past century, open pit mines have steadily increased their production rate by using larger equipments which require intensive capital investment. Low commodity prices have forced companies to decrease their unit cost by improving productivity. One way to improve productivity is to utilize equipment as effectively as possible. Therefore, the accurate estimation of equipment effectiveness is very important so that it can be increased. Overall Equipment Effectiveness (OEE) is a well-known measurement method, which combines availability, performance and quality, for the evaluation of equipment effectiveness in manufacturing industry.
However, there isn’t any study in literature about how to use this metric for mining equipments such as shovel, truck, drilling machine etc. This paper will discuss the application of OEE to measure effectiveness of mining equipment . It identifies causes of time losses for shovel and truck operations and introduces procedure to record time losses. The procedure to estimate OEE of shovels and trucks has also been presented via numerical example.
Introduction
All industries are dependent on their assets as well as mining companies. The increase in automation, compounded by the increase in the size and capacity of equipment over the years has drastically changed the consequences of equipment ineffectiveness. Current economic conditions, severe global competition, environmental regulations and a continually improving focus on safety are also causing mine managers to consider creative and proven methods to determine effectiveness of their equipment so they can take necessary precautions to increase the effectiveness of their equipment and to reduce the total production cost.
Mining is a very capital-intensive industry, and it is known fact that the equipment utilization and accurate estimation of this utilization are very important since mine managers want to utilize their equipment as effectively as possible to get an early return on their investments as well reducing total production cost. Many studies have been carried out on selection of mining equipments [1-5]. But there has been a little attention on the measurement of effectiveness of those equipments. Only maintenance policies have been studied and implemented in order to improve availability of these equipments [6-10]. Therefore the aim of this study is to introduce a method, which is widely accepted in manufacturing industries, used in measuring overall effectiveness of equipments known as Overall Equipment Effectiveness (OEE).
What is OEE?
OEE is a simple tool that will help manager to measure the effectiveness of their equipment. It takes the most common and important sources of productivity loss, which are called six big losses and given in Table 1. These losses are quantified as availability, performance and quality in order to estimate OEE as given in equation: OEE = Availability × Performance × Quality.
OEE for mining equipment
OEE applications in mining industry differ from manufacturing industry. Therefore, it is necessary to develop equipment’s own classification framework for the losses, which should be associated with the components of availability, performance and quality [16]. The necessary data classification to be collected will vary from equipment to equipment. In addition to that, it is more difficult to gather data for mining equipments due to following reasons:
• Mining is a serial operation of drilling-blasting, loading, hauling and dumping. Therefore, the production of equipments used in each step depends on the production of previous equipment. That means utilization of each equipment affects the others.
• The capacity of mining equipment is huge. Therefore the effect of utilization on total production is very high.
• The physical environment under which mining equipment operates is less than ideal.
• The operating environment of the mine is dynamic with many unknowns that can affect the equipment utilization drastically. In this study, OEE of shovels and trucks have been considered since they are the main equipments for the most of the Open Pit Mines.
Conclusions
Utilization of equipment can only be improved and controlled successfully if an appropriate performance measurement system is used. OEE is a known method to measure performance of production equipment in manufacturing industries and adapted for mining industry in this paper. It aims to identify unproductive time losses within the system and these time losses affect availability, performance and quality.
This paper has shown that what are the possible time losses for mining equipments, more specifically shovel and trucks, and how they can be used in the calculation of OEE. The difference between calendar time-based approach and loading time-based approach is also discussed to set benchmark for improvement. Loading time-based approach provides higher OEE values than calendar time-based approach. Therefore, it is important to declare which approach is used when one talks about OEE of any specific equipment.
The importance of proper data collecting system to estimate OEE is also emphasized. If data are not properly collected then the resulting OEE will not be meaningful. Most of the equipment producers provide data collecting system for their equipments, the manager just needs to classify them according to definitions.