Patent Publication Number: US-8982378-B2

Title: Methods and systems for analyzing the impact of machine failure data on a print shop

Description:
BACKGROUND 
     Machines, such as print devices, may fail due to a variety of reasons. Failures can sometimes keep machines out of commission for several hours before they are repaired. In production or service environments where failure to comply with production or service requirements within an allocated time period can lead to penalties, the ability to reduce the impact of such failures and downtime associated with the failures is desirable. 
     SUMMARY 
     This disclosure is not limited to the particular systems, methodologies or protocols described, as these may vary. The terminology used in this description is for the purpose of describing the particular versions or embodiments only, and is not intended to limit the scope. 
     As used in this document, the singular forms “a,” “an,” and “the” include plural reference unless the context clearly dictates otherwise. Unless defined otherwise, all technical and scientific terms used herein have the same meanings as commonly understood by one of ordinary skill in the art. All publications mentioned in this document are incorporated by reference. All sizes recited in this document are by way of example only, and the invention is not limited to structures having the specific sizes or dimensions recited below. Nothing in this document is to be construed as an admission that the embodiments described in this document are not entitled to antedate such disclosure by virtue of prior invention. As used herein, the term “comprising” means “including, but not limited to.” 
     In an embodiment, a method of analyzing failures of a print device may include receiving failure information associated with a print device in a print shop. The failure information may pertain to a plurality of failures experienced by the print device over a period of time. The method may include generating, by a computing device, failure distribution information by, for each pair of consecutive failures in the failure information, determining a time to failure between the pair of consecutive failures, determining a repair time associated with each failure in the pair of consecutive failures, and setting the determined times to failure and the determined repair times as the failure distribution information. The method may include performing, by the computing device, a simulation of processing of one or more print jobs by the print device using the failure distribution information, and displaying one or more results of the simulation to a user. 
     In an embodiment, a system of analyzing failures of a print device may include a computing device and a computer-readable storage medium in communication with the computing device. The computer-readable storage medium may include one or more programming instructions that, when executed, cause the computing device to receive failure information associated with a print device in a print shop. The failure information may pertain to a plurality of failures experienced by the print device over a period of time. The computer-readable storage medium may include one or more programming instructions that, when executed, cause the computing device to generate failure distribution information by, for each pair of consecutive failures in the failure information, determining a time to failure between the pair of consecutive failures, determining a repair time associated with each failure in the pair of consecutive failures, and setting the determined times to failure and the determined repair times as the failure distribution information. The computer-readable storage medium may include one or more programming instructions that, when executed, cause the computing device to perform a simulation of processing of one or more print jobs by the print device using the failure distribution information, and display one or more results of the simulation to a user. 
     In an embodiment, a method of analyzing failures of a plurality of print devices may include receiving failure information associated with a plurality of print devices in a print shop. The failure information may pertain to a plurality of failures experienced by the print devices over a period of time. The method may include generating, by a computing device, failure distribution information associated with each print device in the plurality of print devices by, for each pair of consecutive failures in the failure information, determining a time to failure between the pair of consecutive failures, determining a repair time associated with each failure in the pair of consecutive failures, and setting the determined times to failure and the determined repair times as the failure distribution information. The method may include performing, by the computing device, a simulation of processing of one or more print jobs by the print devices using the failure distribution information associated with the print devices, and displaying one or more results of the simulation to a user. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  illustrates a block diagram of a print shop according to an embodiment. 
         FIG. 2  illustrates a flow diagram of an illustrative method of analyzing the impact of one or more failures according to an embodiment. 
         FIG. 3  illustrates an example of a service log according to an embodiment. 
         FIG. 4  illustrates an example graphical representation showing the periods of downtime experienced by example print devices over a period of time according to an embodiment. 
         FIG. 5  illustrates a block diagram of hardware that may be used to contain or implement program instructions according to an embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     The following terms shall have, for purposes of this application, the respective meanings set forth below: 
     An “autonomous cell” refers to one or more print devices in a print shop that are capable of processing at least a portion of a print job. 
     A “computing device” refers to a device that includes a processor and tangible, computer-readable memory. The memory may contain programming instructions that, when executed by the processor, cause the computing device to perform one or more operations according to the programming instructions. Examples of computing devices include personal computers, servers, mainframes, gaming systems, televisions, and portable electronic devices such as smartphones, personal digital assistants, cameras, tablet computers, laptop computers, media players and the like. 
     A “failure” refers to an event that causes partial or complete cessation of operation of a print device. Examples of failures may include, without limitation, power outages, equipment failure, device overload, paper jams, overheating and/or the like. 
     A “job” refers to a logical unit of work that is to be completed for a customer. A job may include one or more print jobs from one or more clients. A production system may include a plurality of jobs. Although the disclosed embodiments pertain to document production systems, the disclosed methods and systems can be applied to production systems in general. 
     A “meter read” refers to a number of pages processed by a print device at a particular time. For example, two minutes into processing a print job having 1,452,876 pages may have a meter read value of 32,784 pages. Additional and/or alternate meter read values may be used within the scope of this disclosure. 
     A “print job” refers to a job processed in a print shop. For example, a print job may include producing credit card statements corresponding to a certain credit card company, producing bank statements corresponding to a certain bank, printing a document, or the like. Although the disclosed embodiments pertain to print jobs, the disclosed methods and systems can be applied to jobs in general in other production environments, such as automotive manufacturing, semiconductor production and the like. 
     A “print device” refers to a computing device capable of performing one or more functions, operations and/or services on a print job. For example, a print device may provide print-related services for one or more print jobs. A print device may include a printer, multi-function device or other similar equipment that is capable of printing an image on physical media, such as, for example, paper, vinyl, labels and/or the like. 
     A “service log” refers to a record of maintenance, repair or other services performed on one or more print devices. 
     A “time to failure” is a unit of measurement between consecutive failures experienced by a print device. A time to failure may be measured in time, meter reads and/or the like. 
       FIG. 1  shows an example of a print shop  50 . Print jobs may enter the print shop manually or electronically and be collected at an electronic submission system  55 , such as a computing device and/or scanner. Print jobs are sorted and batched at the submission system or another location, such as a workflow management system, before being delivered to one or more print engines, such as a color printer  56 , black-and-white printer  57  and/or a continuous feed printer  58 . Printed documents may exit the print engine and be delivered to one or more finishing devices or areas such as a collator  60 , cutter  62  and/or binder  64 . The finishing areas may include automatic or manual areas for such finishing activities, and they also may include an automatic or manual inserter  70 . Finally, the documents may move to a postage metering station  72  and/or shipping station  74 . Documents for print jobs may move from one location to another in the print shop by automatic delivery or manual delivery, such as by hand or by one or more paper carts  81 - 85 . 
     Different elements of a print shop  50  may require setup time in order to prepare the device to process a particular print job. For example, some print jobs use pre-printed forms, such as bank statements that are pre-printed with the bank&#39;s logo and contact information or credit card statements pre-printed with charge dispute procedures. Forms also may include inserts, such as marketing materials or subscription cards. If a device in a print shop receives two consecutive print jobs that use identical forms, little or no changeover is required between the two print jobs. However, if the forms are different, the print jobs have different setup characteristics, and a significant setup time may be required to load the new form into the device. This is especially noticeable in continuous feed printing devices  58 , where it can take up to 15 minutes or more to load a new form roll. 
       FIG. 2  illustrates a flow diagram of an illustrative method of analyzing the impact of one or more failures according to an embodiment. As illustrated by  FIG. 2 , failure information for one or more print devices may be received  200 . Failure information may include dates, times and/or causes of one or more failures encountered by one or more print devices. For example, failure information may include a time when the print device first encountered the failure, a time when the print device was repaired, a meter reading of the print device when it first encountered the failure, and one or more comments to, for example, explain the cause of the fault. Table 1 illustrates example failure information according to an embodiment. 
     
       
         
           
               
               
               
               
               
               
               
               
             
               
                 TABLE 1 
               
               
                   
               
               
                   
                 Date 
                 Time 
                 Date 
                 Time 
                   
                   
                   
               
               
                 Failure 
                 Failure Was 
                 Failure Was 
                 Device 
                 Device 
                 Meter 
                 Repair 
               
               
                 # 
                 Encountered 
                 Encountered 
                 Was Fixed 
                 Was Fixed 
                 Read 
                 Procedure 
                 Comments 
               
               
                   
               
             
            
               
                 1 
                 11/6/210 
                 15:00 
                 Nov. 6, 2010 
                 21:43 
                 1345689 
                 Normal 
                   
               
               
                 2 
                 Nov. 9, 2010 
                 14:31 
                 Nov. 9, 2010 
                 19:43 
                 1398761 
                 Special 
                 Storm caused 
               
               
                   
                   
                   
                   
                   
                   
                   
                 delay in 
               
               
                   
                   
                   
                   
                   
                   
                   
                 shipping parts 
               
               
                 3 
                 Nov. 14, 2010 
                  2:10 
                 Nov. 14, 2010 
                  6:12 
                 1429011 
                 Normal 
               
               
                 4 
                 Nov. 19, 2010 
                  9:25 
                 Nov. 19, 2010 
                 15:10 
                 1489134 
                 Normal 
               
               
                   
               
            
           
         
       
     
     In an embodiment, failure information may be obtained from one or more service logs associated with one or more print devices. A service log may be a record of actual service-related issues associated with one or more print devices. For example, a service log may be a record of service calls by technical service personnel in the field.  FIG. 3  illustrates an example of a service log for a print device according to an embodiment. 
     In an embodiment, failure information may be received by a computing device from a print device. For example, a print device may send failure information to a computing device regularly, periodically and/or the like. In an embodiment, a print device may send failure information to a computing device in response to receiving a request for the failure information from the computing device. 
     In an alternate embodiment, a computing device may receive failure information from another computing device. For example, a first computing device may store failure information received from one or more print devices. A second computing device in communication with the first computing device may receive failure information from the first computing device. Additional and/or alternate arrangements may be used within the scope of this disclosure. 
     In an embodiment, the failure information that is received may be failure information corresponding to failures that occurred on a certain print device or devices. For example, received failure information may correspond to failures encountered by print devices in a certain print shop. As another example, received failure information may correspond to failures encountered by print devices operated by a certain customer, client or other operator. 
     In an embodiment, received failure information may correspond to failures that occurred over a period of time. For example, received failure information may correspond to faults that occurred on a certain day, over a certain period of days, with a certain number of weeks, months, years and/or the like. Additional and/or alternate time periods may be used within this disclosure. 
     In an embodiment, failure distribution information may be determined  202  based on the received failure information. Failure distribution information may be one or more metrics associated with failure information, such as, for example, a time to failure, a repair time and/or the like. 
     In an embodiment, a time to failure may be determined from failure distribution information for one or more failures in the failure data. A time to failure may be the amount of time between consecutive failures of a print device. For example, if a first failure occurs on a print device at 9 a.m. on a first day, and a second failure is experienced by the print device at 4 p.m. on the same day, the time to failure may be seven hours. In an embodiment, a time to failure may be measured in print shop open time, meaning that only time between consecutive failures during which a print shop is operational is measured. For example, a print shop may be operational between 8 a.m. and 5 p.m. on weekdays. If a first failure occurs at 3 p.m. on a Wednesday and a second failure occurs at 9 a.m. the following day, the time to failure may be three hours. 
     In an embodiment, a time to failure may be measured in terms of the number of meter reads between consecutive failures. As such, a time to failure may not be an amount of time, but rather a number of pages that a print device is able to process between consecutive failures. For example, referring back to Table 1, the time to failure between Failure 1 and Failure 2 may be 53,072 pages (i.e., 1,398,761-1,345,689). Measuring a time to failure in terms of the number of meter reads between consecutive failures may account for variability introduced by highly fluctuating demand. This may be especially true for situations where failures are experienced more when a print device is printing or processing more throughput. 
     In an embodiment, a repair time may be determined for one or more failures in the failure data. A repair time may refer to the amount of time between when a failure is first experienced by a print device and when the failure is repaired. For example, if a failure is experience by a print device at noon and the failure is repaired at 2 p.m. the same day, then the repair time is two hours. Table 2 illustrates examples of times between failures and repair times for the failures illustrated in Table 1. 
     
       
         
           
               
               
               
             
               
                 TABLE 2 
               
               
                   
               
               
                 Failure # 
                 Time between Failures (hours) 
                 Repair Time (hours:minutes) 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
            
               
                 1 
                 N/A 
                 6:43 
               
               
                 2 
                 71.5 
                 5:32 
               
               
                 3 
                 107.7 
                 4:02 
               
               
                 4 
                 127.2 
                 5:55 
               
               
                   
               
            
           
         
       
     
     In an embodiment, one or more simulations may be performed  204  using at least a portion of the failure distribution information. A simulation may analyze the impact of one or more actual failures on the processing time of one or more theoretical or actual jobs. For example, one or more simulations may be performed  204  to determine whether a print shop is able to meet one or more processing deadlines. One or more simulations may be used to determine whether alternative scheduling policies, such as outsourcing jobs, should be considered. Simulations are described in more detail in, for example, at least U.S. Pat. No. 8,164,777 to Rai et al. entitled “Method and apparatus for modeling print jobs,” U.S. Pat. No. 8,111,417 to Rai et al. entitled “Method and apparatus for modeling print jobs.” Example simulations are described in, for example, Discrete-Event Simulation, 5/E; Jerry Banks, John S. Carson, II, Barry L. Nelson, David M. Nicol; Prentice Hall 2010. 
     In an embodiment, certain failure information or data points may be excluded from a simulation. Failure information that is unique to a special failure or event may be excluded. For example, a failure caused by a delay in the arrival of a part because of a hurricane may be considered a special case and excluded from the simulation. In an embodiment, failure information that is to be excluded from a simulation may be identified by a user. For example, a user may select one or more failure data points to exclude from a simulation. A simulation may be performed  204  on the remaining data points. 
     In an embodiment, a simulation may be performed  204  by one or more computing devices. The computing device may identify one or more parameters associated with a simulation, and, in an embodiment, one or more parameters may be provided to a user. For example, one or more parameters and associated values may be displayed to a user. In another embodiment, one or more parameters and corresponding values may be emailed or otherwise sent to a user. 
     In an embodiment, a comparison of parameters and parameter values of two or more simulations may be provided to a user. For example, a first simulation may be performed that does not take any failures into account. A second simulation may be performed which incorporates one or more failures. One or more parameters and parameter values for each of the two simulations may be presented to a user so that the user can compare the parameter values relative to the simulations. 
     The following examples illustrate two simulations that may be performed to analyze the impact of one or more failures on print shop processing times according to an embodiment. The simulations are performed using a print shop having three autonomous cells with one autonomous cell having a color continuous feed printer. In one simulation, the print shop is modeled without taking into account any failures. In the other simulation, the print shop is modeled taking into account failures. In this example, the simulation uses a mean time between failures of 15 hours and a mean repair time of 4 hours. However, additional and/or alternate times between failures, mean times between failures, repair times and/or mean repair times may be used within the scope of this disclosure. 
     Table 3 illustrates example print shop performance metrics for each simulation according to an embodiment. As illustrated by Table 3, Simulation 1 predicts only 23 late jobs, while Simulation 2 predicts 77 late jobs. As such, incorporating failures into a simulation may result in the prediction of many more late jobs than a simulation that does not take failures into account. 
     
       
         
           
               
               
               
             
               
                 TABLE 3 
               
               
                   
               
               
                   
                 Performance Metric - 
                 Performance Metric - 
               
               
                   
                 Simulation 1 (failure 
                 Simulation 2 (failure 
               
               
                 Parameter 
                 not modeled) 
                 modeled) 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
            
               
                 General 
                   
                   
               
               
                 Scheduling policy 
                 EarliestDue 
                 EarliestDue 
               
               
                 SubSequencing 
                 No 
                 No 
               
               
                 Number of cells 
                 4 
                 4 
               
               
                 Batching 
                 Yes (batch limit: 0) 
                 Yes (batch limit: 0) 
               
               
                 Operator limited 
                 No 
                 No 
               
               
                 Started on 
                 Nov. 6, 2011 
                 Nov. 6, 2011 
               
               
                   
                 3:09:22 PM 
                 3:13:10 PM 
               
               
                 Finished on 
                 Nov. 6, 2011 
                 Nov. 6, 2011 
               
               
                   
                 3:09:27 PM 
                 3:13:15 PM 
               
               
                 Elapsed time (s) 
                 5 
                 5 
               
               
                 Simulation start 
                 May 2, 2011 
                 May 2, 2011 
               
               
                   
                 12:10:00 AM 
                 12:10:00 AM 
               
               
                 Simulation end 
                 Jun. 3, 2011 
                 Jun. 3, 2011 
               
               
                   
                 8:44:43 AM 
                 8:44:43 AM 
               
               
                 Makespan (h) 
                 776.58 
                 776.58 
               
               
                 Lateness 
               
               
                 Number of jobs 
                 3106 
                 3106 
               
               
                 Number of jobs 
                 3106 
                 3106 
               
               
                 completed 
               
               
                 Number of late jobs 
                 23 
                 77 
               
               
                 Number of late jobs 
                 0.74 
                 2.48 
               
               
                 (percent) 
               
               
                 Average lateness 
                 −58.46 
                 −56.67 
               
               
                 Median lateness 
                 −57.51 
                 −57.00 
               
               
                 Standard deviation 
                 29.01 
                 31.22 
               
               
                 lateness 
               
               
                 Average lateness (late 
                 8.09 
                 25.55 
               
               
                 jobs only) 
               
               
                 Maximum lateness 
                 18.14 
                 63.17 
               
               
                 Performance 
               
               
                 Average process cycle 
                 17.46 
                 16.79 
               
               
                 efficiency (PCE) 
               
               
                 (percent) 
               
               
                 Median PCE (percent) 
                 2.08 
                 1.86 
               
               
                 Average turnaround 
                 18.89 
                 20.68 
               
               
                 time (TAT) 
               
               
                 Median TAT 
                 10.38 
                 11.14 
               
               
                 Average slowdown 
                 0.56 
                 0.61 
               
               
                 Median slowdown 
                 0.04 
                 0.04 
               
               
                 Average value added 
                 1.34 
                 1.34 
               
               
                 time (VAT) 
               
               
                 Median VAT 
                 0.11 
                 0.11 
               
               
                 Average processing time 
                 8.76 
                 8.86 
               
               
                   
               
            
           
         
       
     
     In an embodiment, one or more results of one or more simulations may be displayed  206  to a user. In an embodiment, at least a portion of the results may be displayed as one or more graphical representations of the impact of failures on a print shop&#39;s productivity. A graphical representation may be a chart, a graph, a table or other visualization. For example,  FIG. 4  illustrates an example graphical representation showing the periods of downtime experienced by example print devices over a period of time according to an embodiment. The illustrated periods of downtime may reflect the times during which the corresponding print devices experience a failure. 
       FIG. 5  depicts a block diagram of hardware that may be used to contain or implement program instructions. A bus  500  serves as the main information highway interconnecting the other illustrated components of the hardware. CPU  505  is the central processing unit of the system, performing calculations and logic operations required to execute a program. CPU  505 , alone or in conjunction with one or more of the other elements disclosed in  FIG. 5 , is an example of a processing device, computing device or processor as such terms are used within this disclosure. Read only memory (ROM)  510  and random access memory (RAM)  515  constitute examples of memory devices. 
     A controller  520  interfaces with one or more optional memory devices  525  to the system bus  400 . These memory devices  525  may include, for example, an external or internal DVD drive, a CD ROM drive, a hard drive, flash memory, a USB drive or the like. As indicated previously, these various drives and controllers are optional devices. 
     Program instructions, software or interactive modules for providing the interface and performing any querying or analysis associated with one or more data sets may be stored in the ROM  510  and/or the RAM  515 . Optionally, the program instructions may be stored on a tangible computer readable medium such as a compact disk, a digital disk, flash memory, a memory card, a USB drive, an optical disc storage medium, such as a Blu-Ray™ disc, and/or other recording medium. 
     An optional display interface  530  may permit information from the bus  500  to be displayed on the display  535  in audio, visual, graphic or alphanumeric format. Communication with external devices, such as a printing device, may occur using various communication ports  540 . A communication port  540  may be attached to a communications network, such as the Internet or an intranet. 
     The hardware may also include an interface  545  which allows for receipt of data from input devices such as a keyboard  550  or other input device  555  such as a mouse, a joystick, a touch screen, a remote control, a pointing device, a video input device and/or an audio input device. 
     It will be appreciated that various of the above-disclosed and other features and functions, or alternatives thereof, may be desirably combined into many other different systems or applications. Also that various presently unforeseen or unanticipated alternatives, modifications, variations or improvements therein may be subsequently made by those skilled in the art which are also intended to be encompassed by the following claims.