Patent Application
20130117162
Embodiments of the present invention relate generally to methods and systems for inventory management and more particularly to allocation of inventory levels throughout a supply chain.
In a multi-echelon supply chain network, demands can occur for many items at one or more internal organizations or customer locations. The source(s) of supplies to meet the demands can come from one or more upstream internal organizations or suppliers. Often times, the demands from the multiple destinations compete for the supplies from the source organization(s) and/or suppliers. If the available supply is less than the demands, the allocations are typically based on demand priority. If there are multiple demands with the same priority, the sequence and amount to fulfill the demands may be random. It is possible that some demands are met completely on time while others do not get any supplies allocated.
Some software solutions provide the ability to “fair share” supplies across competing demands. This is done either based on a user specified percentage or based on the ratio of demand quantities. However, they do this on an item by item basis and offer very limited or no capabilities when the competing demands are for different items and/or come from different locations. They also do not provide the ability to consider supplies that may come from multiple items that are substitutable. In addition, in a service or distribution supply chain, the source for a supply may come from locations upstream (i.e., a different tier) or from locations at the same tier (circular source) where surplus inventory can be shared of allocated. Hence, there is a need for improved methods and systems for fair share allocation of inventory levels throughout a multi-echelon supply chain and across competing demands in the supply chain.
Embodiments of the invention provide systems and methods for fair share allocation of inventory levels throughout a supply chain. According to one embodiment, fair share allocation in a multi-echelon service supply chain that considers supercession and repair relationships can comprise executing a first round main Linear Programming (LP) solve generated initial solution. Post-processing heuristics for fair sharing can be applied to the first round solve of the main LP after executing the first round solve of the main LP. Circular sourcing heuristics can be applied to the first round solve of the main LP when adjusting the first round solve of the main LP for fair sharing allocation requirements. For example, applying the circular sourcing heuristics to the first round solve of the main LP can comprise determining a firmed supply surplus and shortage based on a demand picture from the first round solve of the main LP adjusted for fair sharing. A second round main LP solve can be executed using the fixed inter-organizational transfer variables and fixed supply towards independent demand variables from the post-processing heuristics.
Applying the post-processing heuristics can comprise using a push-down logic to generate a demand picture for each sourcing tier of a plurality of sourcing tiers. Using a push-down logic to generate a demand picture for each sourcing tier can comprises obtaining the supply information from the first round solve of the main LP, choosing a sourcing path of a plurality of sourcing paths of the supply chain, consuming the supply at each location for the selected path, applying supercession at each sourcing location of the selected path, pushing down the remaining demand quantity to a next sourcing tier, and linking a dependent demand to the original demand list for each time bucket, at each organization for each sourcing tier.
Applying the post-processing heuristics can further comprise using a bottom-up logic to adjust the first round solve of the main LP for fair sharing allocation requirements. In such cases, an output of the post-processing heuristics can comprise fixed inter-organizational transfer variables and fixed supply towards independent demand variables. Using a bottom-up logic to adjust the first round solve of the main LP for fair sharing allocation requirements can comprise identifying eligible competing demands, applying fair sharing of supply to those demands, performing bottom up processing to adjust downstream demand satisfaction, re-calculating unsatisfied demands, determining whether any unmet demand remains, and in response to determining unmet demand remains, repeatedly pushing down remaining demand quantities, applying fair sharing between the unmet demands, performing bottom up processing to adjust downstream demand satisfaction, and re-computing unsatisfied demand until no unmet demand remains.
In the following description, for the purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of various embodiments of the present invention. It will be apparent, however, to one skilled in the art that embodiments of the present invention may be practiced without some of these specific details. In other instances, well-known structures and devices are shown in block diagram form.
The ensuing description provides exemplary embodiments only, and is not intended to limit the scope, applicability, or configuration of the disclosure. Rather, the ensuing description of the exemplary embodiments will provide those skilled in the art with an enabling description for implementing an exemplary embodiment. It should be understood that various changes may be made in the function and arrangement of elements without departing from the spirit and scope of the invention as set forth in the appended claims.
Specific details are given in the following description to provide a thorough understanding of the embodiments. However, it will be understood by one of ordinary skill in the art that the embodiments may be practiced without these specific details. For example, circuits, systems, networks, processes, and other components may be shown as components in block diagram form in order not to obscure the embodiments in unnecessary detail. In other instances, well-known circuits, processes, algorithms, structures, and techniques may be shown without unnecessary detail in order to avoid obscuring the embodiments.
Also, it is noted that individual embodiments may be described as a process which is depicted as a flowchart, a flow diagram, a data flow diagram, a structure diagram, or a block diagram. Although a flowchart may describe the operations as a sequential process, many of the operations can be performed in parallel or concurrently. In addition, the order of the operations may be re-arranged. A process is terminated when its operations are completed, but could have additional steps not included in a figure. A process may correspond to a method, a function, a procedure, a subroutine, a subprogram, etc. When a process corresponds to a function, its termination can correspond to a return of the function to the calling function or the main function.
The term “machine-readable medium” includes, but is not limited to portable or fixed storage devices, optical storage devices, wireless channels and various other mediums capable of storing, containing or carrying instruction(s) and/or data. A code segment or machine-executable instructions may represent a procedure, a function, a subprogram, a program, a routine, a subroutine, a module, a software package, a class, or any combination of instructions, data structures, or program statements. A code segment may be coupled to another code segment or a hardware circuit by passing and/or receiving information, data, arguments, parameters, or memory contents. Information, arguments, parameters, data, etc. may be passed, forwarded, or transmitted via any suitable means including memory sharing, message passing, token passing, network transmission, etc.
Furthermore, embodiments may be implemented by hardware, software, firmware, middleware, microcode, hardware description languages, or any combination thereof. When implemented in software, firmware, middleware or microcode, the program code or code segments to perform the necessary tasks may be stored in a machine readable medium. A processor(s) may perform the necessary tasks.
Embodiments of the present invention can include an algorithm to allocate available supply to competing demands while considering the complete supply chain network. The algorithm can address a concern in the service/spares planning industry, where it is very common to have several revisions of an item/product. Embodiments of the present invention can provide: the ability to consider competing demands that could be for different items/revisions; the ability to consider competing demands that could be from different locations; the ability to consider multiple sources and types of supply, including supplies of defectives that need to be repaired before it can be allocated to a demand; the ability to fair share across safety stock demands; selectively enforcing order modifiers and allowing it to be a soft constraint; the ability to use a different bucketing granularity for ‘fair share’ in contrast to the bucketing used for replenishment; and the ability to incorporate rebalancing decisions in-line with fair share. Rebalancing is the process by which locations that are near each other physically can share any excess inventory to allow for a better re-distribution (or rebalancing of excess) of inventory. This process allows inventory to flow in both directions between 2 or more locations.
These features significantly improve the quality of the solution generated by the planning system and helps the planner make the right decisions that address key business metrics such as service level and inventory costs. Embodiments of the present invention can be used, for example, to plan the spares/repair of the service business and help to increase the customer service level while minimizing inventory.
In some embodiments, the system 100 may also include a network 115. The network may be any type of network familiar to those skilled in the art that can support data communications using any of a variety of commercially-available protocols, including without limitation TCP/IP, SNA, IPX, AppleTalk, and the like. Merely by way of example, the network 115 maybe a local area network (“LAN”), such as an Ethernet network, a Token-Ring network and/or the like; a wide-area network; a virtual network, including without limitation a virtual private network (“VPN”); the Internet; an intranet; an extranet; a public switched telephone network (“PSTN”); an infra-red network; a wireless network (e.g., a network operating under any of the IEEE 802.11 suite of protocols, the Bluetooth protocol known in the art, and/or any other wireless protocol); and/or any combination of these and/or other networks such as GSM, GPRS, EDGE, UMTS, 3G, 2.5 G, CDMA, CDMA2000, WCDMA, EVDO etc.
The system may also include one or more server computers 120, 125, 130 which can be general purpose computers and/or specialized server computers (including, merely by way of example, PC servers, UNIX servers, mid-range servers, mainframe computers rack-mounted servers, etc.). One or more of the servers (e.g., 130) may be dedicated to running applications, such as a business application, a web server, application server, etc. Such servers may be used to process requests from user computers 105, 110. The applications can also include any number of applications for controlling access to resources of the servers 120, 125, 130.
The web server can be running an operating system including any of those discussed above, as well as any commercially-available server operating systems. The web server can also run any of a variety of server applications and/or mid-tier applications, including HTTP servers, FTP servers, CGI servers, database servers, Java servers, business applications, and the like. The server(s) also may be one or more computers which can be capable of executing programs or scripts in response to the user computers 105, 110. As one example, a server may execute one or more web applications. The web application may be implemented as one or more scripts or programs written in any programming language, such as Java™, C, C# or C++, and/or any scripting language, such as Perl, Python, or TCL, as well as combinations of any programming/scripting languages. The server(s) may also include database servers, including without limitation those commercially available from Oracle®, Microsoft®, Sybase®, IBM® and the like, which can process requests from database clients running on a user computer 105, 110.
In some embodiments, an application server may create web pages dynamically for displaying on an end-user (client) system. The web pages created by the web application server may be forwarded to a user computer 105 via a web server. Similarly, the web server can receive web page requests and/or input data from a user computer and can forward the web page requests and/or input data to an application and/or a database server. Those skilled in the art will recognize that the functions described with respect to various types of servers may be performed by a single server and/or a plurality of specialized servers, depending on implementation-specific needs and parameters.
The system 100 may also include one or more databases 135. The database(s) 135 may reside in a variety of locations. By way of example, a database 135 may reside on a storage medium local to (and/or resident in) one or more of the computers 105, 110, 115, 125, 130. Alternatively, it may be remote from any or all of the computers 105, 110, 115, 125, 130, and/or in communication (e.g., via the network 120) with one or more of these. In a particular set of embodiments, the database 135 may reside in a storage-area network (“SAN”) familiar to those skilled in the art. Similarly, any necessary files for performing the functions attributed to the computers 105, 110, 115, 125, 130 may be stored locally on the respective computer and/or remotely, as appropriate. In one set of embodiments, the database 135 may be a relational database, such as Oracle 10 g, that is adapted to store, update, and retrieve data in response to SQL-formatted commands.
The computer system 200 may additionally include a computer-readable storage media reader 225a, a communications system 230 (e.g., a modem, a network card (wireless or wired), an infra-red communication device, etc.), and working memory 240, which may include RAM and ROM devices as described above. In some embodiments, the computer system 200 may also include a processing acceleration unit 235, which can include a DSP, a special-purpose processor and/or the like.
The computer-readable storage media reader 225a can further be connected to a computer-readable storage medium 225b, together (and, optionally, in combination with storage device(s) 220) comprehensively representing remote, local, fixed, and/or removable storage devices plus storage media for temporarily and/or more permanently containing computer-readable information. The communications system 230 may permit data to be exchanged with the network 220 and/or any other computer described above with respect to the system 200.
The computer system 200 may also comprise software elements, shown as being currently located within a working memory 240, including an operating system 245 and/or other code 250, such as an application program (which may be a client application, web browser, mid-tier application, RDBMS, etc.). It should be appreciated that alternate embodiments of a computer system 200 may have numerous variations from that described above. For example, customized hardware might also be used and/or particular elements might be implemented in hardware, software (including portable software, such as applets), or both. Further, connection to other computing devices such as network input/output devices may be employed. Software of computer system 200 may include code 250 for implementing embodiments of the present invention as described herein.
After the first round solve of main LP, post-processing heuristics can be applied 310 for fair sharing. According to one embodiment, the post-processing heuristics can use push-down logic such as described below with reference to
Since some applications also use circular sourcing, any defined circular sourcing heuristics can be applied 315 after or in-line with fair-sharing heuristics. In circular sourcing heuristics, the firmed supply surplus and shortage can be calculated based on demand picture from fair-sharing allocation (including both independent demand and dependent demand).
Once post-processing heuristics have been applied 310 and 315, a second round solve of main LP can be executed 320 starting from demand LPs. With fixed variables passed from post-processing heuristics, the second solve of main LP can generate a solution which is in line with fair-sharing allocation requirement.
Stated another way, fair share allocation in a multi-echelon service supply chain that considers supercession and repair relationships can comprise executing 305 a first round main Linear Programming (LP) solve generated initial solution and applying 310 post-processing heuristics for fair sharing to the first round solve of the main LP after executing the first round solve of the main LP. Applying 310 the post-processing heuristics can comprise using a push-down logic to generate a demand picture for each sourcing tier of a plurality of sourcing tiers. Applying 310 the post-processing heuristics further can also comprise using a bottom-up logic to adjust the first round solve of the main LP for fair sharing allocation requirements. An output of such post-processing heuristics can comprise fixed inter-organizational transfer variables and fixed supply towards independent demand variables. In some cases, circular sourcing heuristics can also be applied 315 to the first round solve of the main LP after adjusting the first round solve of the main LP for fair sharing allocation requirements. Applying 315 the circular sourcing heuristics, if any, to the first round solve of the main LP can comprise determining a firmed supply surplus and shortage based on a demand picture from the first round solve of the main LP adjusted for fair sharing. A second round main LP solve can be executed 320 using the fixed inter-organizational transfer variables and fixed supply towards independent demand variables from the post-processing heuristics.
More specifically, generating 410-445 the demand picture for each item-org at each sourcing tier can include choosing a sourcing path 410. In case there are multiple sourcing paths available, the one with the least cumulative LT can be selected. If there are multiple paths with the same cumulative LT, one path can be randomly picked. For the selected path, the supply at the given org can be consumed 415. Supercession can then be applied 420. More specifically, for any given demand, at each sourcing tier/org, the supply of the demand item at the given org can be consumed. Then, the supply of its higher revision item can be consumed, and the remaining demand quantity can be pushed down 425 to the next sourcing tier. For each time bucket, at each org for each sourcing tier a dependent demand can be linked 440 to the original demand list.
Stated another way, the flow of push-down heuristics (for supercession chain A->B->C) can be outlined as:
A determination 520 can then be made as to whether any unmet demand remains. In response to determining 520 that no unmet demand remains, processing may end. However, in response to determining 520 that some unmet demand remains, remaining demand quantities can be pushed down, fair sharing between the unmet demands can be applied 530, bottom up processing 532 can be done to adjust downstream demand satisfaction, and unsatisfied demand can be re-computed 535. The process of pushing down 525 remaining demand quantity, applying 530 fair sharing across those demands, bottom up processing 532 can be done to adjust downstream demand satisfaction, and re-computing 535 unsatisfied demand can be repeated until a determination 520 is made that no unmet demand remains.
Stated another way, this bottom-up logic can be outlined as follows (with item supercession A->B->C):
According to one embodiment, when the fair-sharing should be supported on good components of WOs, the processes described above can be modified to support these cases. For example, if the WO has more than one good components (say components B and C), then fair-sharing can be consistent on all the good components, i.e., fair-sharing quantity on components=minimum (component B qty, component C qty) with the component usage accounted. If good the component also has independent demand, then in the above heuristics, it can do fair-sharing on assembly items first, then do fair-sharing on component level (including both independent demand and component demand from assembly item).
In the foregoing description, for the purposes of illustration, methods were described in a particular order. It should be appreciated that in alternate embodiments, the methods may be performed in a different order than that described. It should also be appreciated that the methods described above may be performed by hardware components or may be embodied in sequences of machine-executable instructions, which may be used to cause a machine, such as a general-purpose or special-purpose processor or logic circuits programmed with the instructions to perform the methods. These machine-executable instructions may be stored on one or more machine readable mediums, such as CD-ROMs or other type of optical disks, floppy diskettes, ROMs, RAMs, EPROMs, EEPROMs, magnetic or optical cards, flash memory, or other types of machine-readable mediums suitable for storing electronic instructions. Alternatively, the methods may be performed by a combination of hardware and software.
While illustrative and presently preferred embodiments of the invention have been described in detail herein, it is to be understood that the inventive concepts may be otherwise variously embodied and employed, and that the appended claims are intended to be construed to include such variations, except as limited by the prior art.
The present application claims benefit under 35 USC 119(e) of U.S. Provisional Application No. 61/556,383, filed on Nov. 7, 2011 by Feng et al. and entitled “A Method for Fair Share Allocation in a Multi-Echelon Service Supply Chain that Considers Supercession and Repair Relationships,” of which the entire disclosure is incorporated herein by reference for all purposes.
| Number | Date | Country | |
|---|---|---|---|
| 61556383 | Nov 2011 | US |
