Patent Application
20180150917
Aspects of the disclosure are related to manufacturing equipment and processes, and in particular, to manufacturing equipment and processes in industrial automation applications.
With regard to manufacturing equipment or processes, process indicators (e.g., cost per unit, time per unit, etc.) may be indicative of overall equipment effectiveness (OEE). OEE quantifies how well a manufacturing system performs relative to its designed capacity. For example, OEE may quantify availability, performance, and quality. Availability represents the percentage of scheduled time (i.e., uptime) that the operation is available to operate. Performance represents the speed at which the machine or process runs as a percentage of its designed speed, and quality represents the good units produced as a percentage of the total units started.
While the traditional OEE equation quantifies availability, performance, and quality, other manufacturing metrics may further elucidate the effectiveness of the manufacturing equipment or processes. For example, in order to be functional in some manufacturing processes, certain manufacturing equipment requires energy to operate. The traditional OEE equation that incorporates the availability and performance of a machine or other manufacturing equipment during the manufacturing process fails to indicate effectiveness of the equipment or process based on the energy used and properly allocated during the process.
Provided herein are systems, methods, and software for calculating energy effectiveness in an industrial automation system. In one implementation, one or more computer-readable storage media having program instructions stored thereon to calculate energy effectiveness in an industrial automation system, wherein the program instructions, when executed by a computing system, direct the computing system to at least acquire production energy information indicating the amount of energy used by a machine of the industrial automation system during a processing period in which the machine was processing one or more parts configured to be processed by the machine and acquire process energy information indicating the sum of energy used by the machine during the processing period in which the machine was processing the one or more parts and in which the machine was not processing any parts. The instructions further direct the computing system to acquire a total part value indicating the total number of parts expected to be processed by the machine during the processing period, acquire a good part value indicating the total number of good parts processed by the machine during the processing period, calculate an overall equipment energy effectiveness (OEEE) of the industrial automation system based on a ratio of the production energy information to the process energy information and based on a ratio of the good part value to the total part value, and display the OEEE to a user.
In another implementation, a method for calculating energy effectiveness in an industrial automation system comprises acquiring production energy information indicating the amount of energy used by a machine of the industrial automation system during a processing period in which the machine was processing one or more parts configured to be processed by the machine and acquiring process energy information indicating the sum of energy used by the machine during the processing period in which the machine was processing the one or more parts and in which the machine was not processing any parts. The method further comprises acquiring a total part value indicating the total number of parts expected to be processed by the machine during the processing period, acquiring a good part value indicating the total number of good parts processed by the machine during the processing period, calculating an overall equipment energy effectiveness (OEEE) of the industrial automation system based on a ratio of the production energy information to the process energy information and based on a ratio of the good part value to the total part value, and displaying the OEEE to a user.
In another implementation, a system to calculate energy effectiveness in an industrial automation system comprises an upstream machine configured to perform a first function to produce a first measurable outcome, an industrial machine configured to perform a second function based on the first measurable outcome to produce a second measurable outcome, a downstream machine configured to perform a third function based on the second measurable outcome to produce a third measurable outcome, and a controller. The controller is programmed to acquire production energy information indicating the amount of energy used by each of the upstream, industrial, and downstream machines to respectively perform the first, second, and third functions during a processing period; and acquire a success value indicating the total number of successful performances of the first, second, and third functions respectively processed by the upstream, industrial, and downstream machines during the processing period. The controller is also programmed to acquire total energy information indicating the sum of energy respectively used by the upstream, industrial, and downstream machines during the processing period in which the first, second, and third functions were respectively performed and in which the no functions were respectively performed by the upstream, industrial, and downstream machines; acquire a total outcome value indicating the total number of measurable outcomes expected to be produced by the respective upstream, industrial, and downstream machines during the processing period; and calculate an overall equipment energy effectiveness (OEEE) for each of the upstream, industrial, and downstream machines based on a respective ratio of the production energy information to the total energy information and based on a respective ratio of the success values to the total outcome value.
This Overview is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. It should be understood that this Overview is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.
Many aspects of the disclosure can be better understood with reference to the following drawings. While several implementations are described in connection with these drawings, the disclosure is not limited to the implementations disclosed herein. On the contrary, the intent is to cover all alternatives, modifications, and equivalents.
The following description and associated figures teach the best mode of the invention. For the purpose of teaching inventive principles, some conventional aspects of the best mode may be simplified or omitted. The following claims specify the scope of the invention. Note that some aspects of the best mode may not fall within the scope of the invention as specified by the claims. Thus, those skilled in the art will appreciate variations from the best mode that fall within the scope of the invention. Those skilled in the art will appreciate that the features described below can be combined in various ways to form multiple variations of the invention. As a result, the invention is not limited to the specific examples described below, but only by the claims and their equivalents.
Implementations described herein provide for OEE calculation taking energy used in the manufacturing process into account. In at least one implementation disclosed herein, energy used by one machine because of a delay caused by another machine is attributed to the delay-causing machine. In this manner, the OEE with energy calculation results may be analyzed to identify potential issue spots for further analysis and/or maintenance.
where the total energy consumed is the total amount of energy used during a given measurement period (e.g., a production shift), the working energy consumed is the amount of energy used during working periods within the given period, good parts is the number of parts or units produced that meet expectations versus the total amount of parts started or intended to be produced including parts that do not meet expectations and are discarded or otherwise disposed of.
While the examples and discussion herein refer to parts that are produced or processed by machines at output units, other types of output units are allowed within the scope of the embodiments of the invention described herein. For example, a machine may perform a service that does not process a part or supply material into a different part. In this case, the service may be considered to be the part processed by the machine. Any function for which the machine is designed to perform may be counted as a “part” for the purposes of this disclosure even though a physical unit may not be a result of the outcome of performing the function.
To begin the calculation of finding the OEEE of a manufacturing system or process, operation 100 begins with acquiring the total energy consumed 102, the working energy consumed 104, the number of total parts 106, and the number of good parts 108. The energy and part information may be obtained from previously measured values stored in a database or may be obtained on the fly. In one embodiment, the data may be stored in a data historian of a manufacturing system. The part produced by any one machine may not be the final part ready for sale or use in some other manner. For example, in a serial-type production line, the “part” produced by a mixing machine may be a mixture of a plurality of ingredients for use by a downstream machine such as an oven or pressure machine configured to process the mixture into a different form. Each machine may be configured to continue working on a supplied “part” by an upstream machine until a final, sellable good part is produced at the end of the process. Accordingly, the “part” each machine is configured to produce is relative to what the machine is configured to produce, and this part may not be the final part ready for sale or use. Table 1 below includes sample numbers for an example manufacturing process. For example, Table 1 may represent data from a single work shift at a manufacturing facility.
After the data are acquired, a percent of working energy (PWE) is calculated 110 in the first half of Eqn. 1 by dividing the working energy consumed by the total energy consumed. The percent of good parts (PGP) is calculated 112 in the second half of Eqn. 1 by dividing the number of sellable, approved, or otherwise good parts or units produced by the number of total parts or units that were expected to be produced. By multiplying the PWE by the PGP, the OEEE can then be determined 114. Once calculated, the OEEE value can be displayed 116 to a user or put into a human-readable report for consideration and/or analysis.
While operation 100 can be used to determine the OEEE for the entire manufacturing system, for a sub-group (e.g., a manufacturing line) of the manufacturing system, or even for a particular machine or asset in the manufacturing process, a more detailed analysis of the OEEE may be desirable. For instance, the percent of working energy of an entire line of manufacturing machines may not tell the complete story about the efficiency of the individual machines relative to the energy used. As used herein, machine refers to any machine, asset, or other manufacturing system component using energy during the manufacturing process.
In this well-optimized example, the manufacturing lines 202-206 are running at 100% efficiency where none of the machines 208-214 experience inefficiencies such as 1) periods of blockages where they are able to supply finished product to the next downstream machine but the downstream machine is not available to receive it, 2) periods of starvation where they are able to receive product from an upstream machine but the upstream machine is not yet able to supply it, or 3) periods of down time or idle time where they are themselves the cause of downstream blockage or upstream starvation. Other inefficiencies of energy usage may be caused by potential stored energy, other types of non-productive states of the machine caused by upstream or downstream machines not being able to perform or operate, or if there is nothing for the machine to do. When the manufacturing lines 202-206 are running at 100% efficiency, the calculation of OEEE according to Eqn. 1 above may suffice for a user's understanding of the efficiency of the lines 202-206. However, the global evaluation of the entire manufacturing line using operation 100 does not elucidate a more granular view of the efficiency of the line when the machines 208-214 work at less than 100% efficiency. Furthermore, evaluating each machine 208-214 separately using operation 100 does not represent a fuller understanding of the OEEE of the machine as may come from incorporating less than 100% efficiencies into the calculation.
Therefore,
To begin the calculation of finding the OEEE of a manufacturing system or process and referring to
After the data are acquired, productive energy consumed (PEC) for each machine 208-214 may be calculated 316 according to:
Total Energy Consumed−Unproductive energy (Eqn. 2),
where the unproductive energy is a summation of the blocked energy, the starved energy, and the downtime energy of each machine 208-214.
Next, an energy liability for each machine 208-214 is calculated 318 according to:
Productive energy+Allocated energy modification (Eqn. 3),
where the allocated energy modification is a summation of the energy measured during downtime periods of a particular machine as well as any blocked energy of an upstream machine and any starved energy of a downstream machine caused by the period of down time by the particular machine. The energy liability calculation thus re-assigns or allocates unproductive energy to the machine 208-214 causing the unproductive energy. For each machine 208-214 experiencing periods of down time, the energy measured during such downtime periods as well as any upstream blocked energy and any downstream starved energy caused by machine down time is assigned to the responsible machine. In the case where multiple machines 208-214 experience periods of down time, timestamps of the relative measured unproductive energy may be used to properly assign unproductive energy to the appropriate machine 208-214.
A re-allocation OEEE for each machine 208-214 of the one or more lines 202-206 may then be based on the following equation:
where the total energy consumed is the total amount of energy used by all machines 208-214 of one or more lines 202-206 during a given measurement period.
In Eqn. 4, a percent of energy liability (PEL) is calculated 320 by dividing the energy liability of consumed energy by the total energy consumed by all machines under consideration. A part quality that indicates the percent of good parts (PGP) is calculated 322 by dividing the number of sellable, approved, or otherwise good parts or units produced by the number of total parts or units that were expected to be produced. By multiplying the PEL by the PGP, the re-allocation OEEE can then be determined 324. Once calculated, the re-allocation OEEE value can be displayed 326 to a user or put into a human-readable report for consideration and/or analysis.
In the example data shown, slicer 212 experienced some down time during the shift. This down time resulted in 5 kW of unproductive energy being used by slicer 212. Because of the down time of slicer 212, both the mixer 208 and the oven 210 experienced 2 kW and 3 kW of unproductive blocked energy, respectively, since slicer 212 could not receive product during its down time. In addition, packager 214 experienced 5 kW of starved unproductive energy for being available to receive product but being starved of product due to the slicer 212 not supplying product during its down time.
As shown, the unproductive energy calculated in step 316 of operation 300 resulted in a total unproductive energy of 15 kW. Since slicer 212 was the only machine to suffer down time during this shift and since the unproductive blocked and starved energies experienced by mixer 208, oven 210, and packager 214 were due to the down time of slicer 212, all of the energy of the unproductive blocked and starved energies is re-allocated to the slicer 212 in step 318 of operation 300.
The percent of working energy (PWC) calculated in step 110 and the percent of energy liability (PEL) calculated in step 320 are illustrated side-by-side in chart 400, and differences between this data can be seen. Since operation 100 does not take energy liability into consideration, the PWC data show an accurate measurement of the energy used by the respective machines, but the values for the mixer 208, oven 210, and packager 214 are higher than they should be and the value for the slicer 212 is lower than it should be because of the down time of slicer 212. Accordingly, the PEL data re-allocates the energy usage to the cause of the extra energy used.
The total parts column shows that, for the shift, 100 units were expected to be produced. However, the first machine in the process (i.e., mixer 208) only produced 95 good/approved units. Since the units produced by each machine 208-212 in line 1202 are used to supply starting material for the next units 210-214, products that fail to pass inspection or to otherwise be labelled as not good units are not counted against the part quality of the downstream units. That is, since mixer 208 produced 5 bad parts, those bad parts are not counted against the oven 210 in being able to successfully produce its parts. Accordingly, the total number of good parts expected to be produced by each downstream machine is reduced by the number of bad parts produced by upstream machines.
While chart 400 illustrates a simple example, a more advanced data analysis may be considered. For example, if the parts exiting any one machine are determined to be bad prior to their introduction to the next machine, the bad part may be removed from the process such that it is not supplied to downstream machines for further processing. In this case, the downstream machines would experience starved energy states that could be re-allocated to the machine producing the bad part. Alternatively, if the bad part is allowed to be processed by the downstream machines to the conclusion of the process, the energy expended by the downstream machines may be allocated back to the machine producing the bad part. In this case, a more detailed measurement of the energy used based on a part-by-part basis can be used to attribute the relevant bad-part-processing energy to the machine that produced the bad part.
Turning now to
Industrial automation environment 700 comprises an automobile manufacturing factory, food processing plant, oil drilling operation, microprocessor fabrication facility, or some other type of industrial enterprise. Machine system 704 could comprise a sensor, drive, pump, filter, drill, motor, robot, fabrication machinery, mill, printer, or any other industrial automation equipment, including their associated control systems. A control system comprises, for example, industrial controller 706, which could include automation controllers, programmable logic controllers (PLCs), programmable automation controllers (PACs), or any other controllers used in automation control. Additionally, machine system 704 could comprise other industrial equipment, such as a brew kettle in a brewery, a reserve of coal or other resources, or any other element that may reside in an industrial automation environment 700.
Machine system 704 continually produces operational data over time. The operational data indicates the current status of machine system 704, such as parameters, pressure, temperature, speed, energy usage, operational equipment effectiveness (OEE), mean time between failure (MTBF), mean time to repair (MTTR), voltage, throughput volumes, times, tank levels, or any other performance status metrics. The operational data may comprise dynamic charts or trends, real-time video, or some other graphical content. Machine system 704 and/or controller 706 is capable of transferring the operational data over a communication link to database system 708, application integration platform 710, and computing system 702, typically via a communication network. Database system 708 could comprise a disk, tape, integrated circuit, server, or some other memory device. Database system 708 may reside in a single device or may be distributed among multiple memory devices.
Application integration platform 710 comprises a processing system and a communication transceiver. Application integration platform 710 may also include other components such as a router, server, data storage system, and power supply. Application integration platform 710 provides an example of application server 130, although server 130 could use alternative configurations. Application integration platform 710 may reside in a single device or may be distributed across multiple devices. Application integration platform 710 may be a discrete system or may be integrated within other systems—including other systems within industrial automation environment 700. In some examples, application integration platform 710 could comprise a FactoryTalk® VantagePoint server system provided by Rockwell Automation, Inc.
The communication links over which data is exchanged between machine system 704, industrial controller 706, database system 708, application integration platform 710, and communication interface 712 of computing system 702 could use metal, air, space, optical fiber such as glass or plastic, or some other material as the transport medium—including combinations thereof. The communication links could comprise multiple network elements such as routers, gateways, telecommunication switches, servers, processing systems, or other communication equipment and systems for providing communication and data services. These communication links could use various communication protocols, such as TDM, IP, Ethernet, telephony, optical networking, packet networks, wireless mesh networks (WMN), local area networks (LAN), metropolitan area networks (MAN), wide area networks (WAN), hybrid fiber coax (HFC), communication signaling, wireless protocols, communication signaling, peer-to-peer networking over Bluetooth, Bluetooth low energy, Wi-Fi Direct, near field communication (NFC), or some other communication format, including combinations thereof. The communication links could be direct links or may include intermediate networks, systems, or devices.
Computing system 702 may be representative of any computing apparatus, system, or systems on which the event data saving processes disclosed herein or variations thereof may be suitably implemented. Computing system 702 provides an example of a computing system that could be used as either a server or a client device in some implementations, although such devices could have alternative configurations. Examples of computing system 702 include mobile computing devices, such as cell phones, tablet computers, laptop computers, notebook computers, and gaming devices, as well as any other type of mobile computing devices and any combination or variation thereof. Examples of computing system 702 also include desktop computers, server computers, and virtual machines, as well as any other type of computing system, variation, or combination thereof. In some implementations, computing system 702 could comprise a mobile device capable of operating in a server-like fashion which, among other uses, could be utilized in a wireless mesh network.
Computing system 702 includes processing system 77, storage system 716, software 718, communication interface 712, and user interface 720. Processing system 77 is operatively coupled with storage system 716, communication interface 712, and user interface 720. Processing system 77 loads and executes software 718 from storage system 716. Software 718 includes application 722 and operating system 724. Application 722 may include event data saving processes 100, 300 in some examples. When executed by computing system 702 in general, and processing system 77 in particular, software 718 directs computing system 702 to operate as described herein for event data saving processes 100, 300 or variations thereof. In this example, user interface 720 includes display system 726, which itself may be part of a touch screen that also accepts user inputs via touches on its surface. Computing system 702 may optionally include additional devices, features, or functionality not discussed here for purposes of brevity.
The functional block diagrams, operational sequences, and flow diagrams provided in the Figures are representative of exemplary architectures, environments, and methodologies for performing novel aspects of the disclosure. While, for purposes of simplicity of explanation, the methodologies included herein may be in the form of a functional diagram, operational sequence, or flow diagram, and may be described as a series of acts, it is to be understood and appreciated that the methodologies are not limited by the order of acts, as some acts may, in accordance therewith, occur in a different order and/or concurrently with other acts from that shown and described herein. For example, those skilled in the art will understand and appreciate that a methodology could alternatively be represented as a series of interrelated states or events, such as in a state diagram. Moreover, not all acts illustrated in a methodology may be required for a novel implementation.
The included descriptions and figures depict specific implementations to teach those skilled in the art how to make and use the best mode. For the purpose of teaching inventive principles, some conventional aspects have been simplified or omitted. Those skilled in the art will appreciate variations from these implementations that fall within the scope of the invention. Those skilled in the art will also appreciate that the features described above can be combined in various ways to form multiple implementations. As a result, the invention is not limited to the specific implementations described above, but only by the claims and their equivalents.
