The disclosure relates to a visual scheduling tool for optimizing capacity utilization, for displaying the likelihood of satisfying customer demand, and for capacity and resource planning in a manufacturing environment.
A Heijunka box is a visual scheduling tool that may be used in Heijunka, where Heijunka is a mechanism to achieve a smoother flow of production of parts. While Heijunka refers to the mechanism for achieving production smoothing, the Heijunka box is the name of a specific tool used in achieving the goals of Heijunka.
The Heijunka box may comprise a schedule that may be divided into a grid of boxes (or a set of pigeon-holes or rectangular receptacles). Each column of boxes may represent a specific period of time, and lines may he drawn down the schedule to visually break the schedule into columns of individual shifts or days or weeks. Cards representing individual jobs (referred to as Kanban cards) may be placed on the Heijunka box to provide a visual representation of upcoming production runs.
The Heijunka box may make it easy for operators to see what type of jobs are queued for production and for when such jobs are scheduled. Workers on the factory floor may remove the Kanban cards for the current period from the box in order to determine what tasks to perform.
Provided are an apparatus, a method, a computational system, and a computer readable storage medium in which one or more regions in a first element that is fixed correspond to indications of a likelihood of satisfying customer demand while optimizing capacity utilization. Customer requirements are stored in a second element that is movable, wherein the one or more regions in the first element are interpreted to determine the likelihood of satisfying customer demand while optimizing capacity utilization, based on the stored customer requirements.
In certain embodiments, the customer requirements are included in one or more cards that include order information, wherein the one or more cards are placed in, or removed from locations in the second element.
In additional embodiments, the first element is an inner wheel that cannot be rotated, and the second element is an outer wheel that is rotated, in response to a selected location in the second element being emptied of cards.
In further embodiments, the one or more regions in the first element are color coded to provide indications of inventory states.
In yet further embodiments, a first color coding indicates that there is insufficient inventory, and a second color coding indicates that there is excessive inventory.
In still further embodiments, a third color coding indicates that inventory and customer demand are in balance.
In additional embodiments, the first element and the second element together comprise a visual scheduling tool.
In yet additional embodiments, the first element and the second element are coupled mechanically, wherein the first element is physically rotated by an operator.
In certain embodiments, a planning chart is used to generate a mapping of cards of the second element to the indications of the likelihood of satisfying customer demand of the first element.
Referring now to the drawings in which like reference numbers represent corresponding parts throughout:
In the following description, reference is made to the accompanying drawings which form a part hereof and which illustrate several embodiments. It is understood that other embodiments may be utilized and structural and operational changes may be made.
Certain embodiments provide a visual scheduling tool for optimizing capacity utilization. Certain embodiments display the likelihood of satisfying customer demand to an operator, such that the operator may take remedial action to speed up or slow down, or to maintain the rate of batch manufacturing of parts in a batch manufacturing environment. Certain embodiments maximize profitability while satisfying customer demand within the promised lead time. Overburdening and unevenness is reduced in the manufacturing environment.
The inventory 104 refers to the amount or number of parts or material that is already available for shipment to customers. The capacity utilization 106 refers to the number of parts or amount of material per unit time that the machine is producing. For example, the machine may have a capacity to produce 5 parts per hour. The information on customer demand 108 may include information such as the promised lead time to the customer, the customer demand, etc.
The scheduling wheel 102 is loaded with cards 110 that comprise customer requirements. For example, an exemplary card may indicate that production of ten parts is needed. The cards 110 are loaded to the scheduling wheel 102 based on customer orders that arrive.
A planning chart 112 that may comprise a spreadsheet may be used to configure the scheduling wheel 102, before the scheduling wheel 102 is used for managing inventory for a machine in a batch production environment. The configuration of the scheduling wheel 102 may be based on the cycle time 120, the lead time 122, and the daily demand 124 that may be used to optimize the capacity utilization 106.
Therefore,
The outer wheel 202 has a plurality of pegs towards the periphery of the outer wheel, and certain exemplary pegs are shown via reference numeral 208. The number of pegs may be different in different embodiments. The pegs are used to hang cards that include customer requirements, such as customer orders. In alternative embodiments mechanisms that are different from pegs may be used to couple or associate work orders to the mechanisms.
In certain embodiments, the inner wheel 204 is fixed and regions of the inner wheel are color coded. Exemplary color codings of the inner wheel into yellow, green, and red regions are shown. For example region 210 is colored yellow, region 212 is colored green, and region 214 is colored red. Instead of color other mechanisms, such as shading, numbering, or textual indications, may be used to indicate different regions of the inner wheel 204.
The inner wheel 204 and the outer wheel 202 are both disc shaped and may be constructed from plastic, paper'board, or any other type of material. In alternative embodiments, the inner wheel 204 and the outer wheel 202 may be shaped differently.
Therefore,
Each card corresponds to a batch of parts that are to be produced in a batch production environment. In a batch production environment the time taken for each hatch of parts to be produced is substantially the same. For example, if a batch can produce a maximum of 100 parts then whether the card indicates that 2 parts are to be produced or 75 parts are to be produced the time taken is substantially the same.
As cards with order requirements arrive, the cards are first placed on peg 309 that may be referred to as the reference peg. Each peg has a maximum number of cards that may be hung on the peg. In
The operator removes the card 306 from peg 309 to produce a batch of parts in a machine. Then he removes the card 304 to produce the next batch of parts, and then he removes card 302 to produce the next batch of parts. The cards from the peg 309 may be removed in any order. Once cards 306, 304, 302 are removed from peg 309, the peg 309 is empty and the outer wheel is rotated anticlockwise so that peg 310 occupies the position that was previously occupied by peg 309, i.e., peg 310 is now the new reference peg and cards are removed from peg 310.
It should be noted that the operator places cards in pegs in a clockwise direction and after each peg is full proceeds to the next peg. Cards are always removed only from the reference peg, and after the reference peg is empty the outer wheel 202 is rotated in an anticlockwise direction to make the next peg the reference peg.
In certain alternative embodiments, the total amount of time spent to fulfil requirements indicated on the cards placed on each peg is the same. For example in certain embodiments, a first peg may have two cards each of which takes three hours, whereas a second peg may have three cards each of which takes two hours, and a third peg may have two cards in which the first card takes one hour and the second card takes five hours. In such embodiments, each peg corresponds to six hours.
The exemplary card 400 may also have optional indicators that show the number of days in which the part is needed by the customer (shown via reference numeral 406) and other information 408, such as detailed part specifications.
The exemplary card 400 may be generated by planning personnel or a computer program, based on customer orders that may be received by a manufacturer. An operator of the scheduling wheel places the exemplary card 400 on a peg of the outer wheel.
When the exemplary card 400 is removed from the peg, after the peg has become the reference peg, the operator produces the quantity of parts in a single batch based on the information included in indicators 402, 404.
The color coded regions of the inner wheel is used to determine whether the inventory of parts is insufficient, excessive or in balance with customer demand. For example, in certain embodiments, the color coding of red 502 indicates that there is insufficient inventory 504 and operators are to remove cards from pegs and start the batch manufacturing production and possibly accelerate such production by employing more resources or personnel. The color coding of 506 may indicate that there is excessive inventory 508 and the batch production process may be idled to allow customer orders to arrive. If the color coding is green 510 it may indicate that the inventory is in balance with customer demand.
At block 602, the operator places cards in the pegs of the outer wheel as orders arrive. At block 604 the operator removes cards from pegs to produce parts, and as the reference peg is emptied the outer wheel is rotated.
The visual inspection of the color in the inner wheel based on which pegs have cards allows the operator to determine the state of the inventory and to determinate when to add or remove resources or shifts to the batch production environment as the demand load changes (shown via reference numeral 606, 608).
Therefore
The design of the scheduling wheel can easily accommodate demand variations of 50%. However if there is an excessive demand change (e.g., a 300% demand change) then the scheduling wheel may have to be redesigned. The demand may be a projected demand based on prior historical pattern of demand or may be based on marketing analysis of projected future sales in the event of introduction of a new product.
The computational device 1202 may include a scheduling wheel application 1206 implemented in software, firmware, hardware or any combination thereof. The scheduling wheel application 1206 may simulate via, execution of a computer program a display 1208 of the scheduling wheel and the operations of the scheduling wheel described in
Control starts at block 1502 in which a scheduling wheel or other manufactured or displayed apparatus indicates a likelihood of satisfying customer demand while optimizing capacity utilization in one or more regions of a first element that is fixed. Customer requirements are stored (at block 1504) in a second element that is movable. The one or more regions in the first element are interpreted (at block 1506) to determine the likelihood of satisfying customer demand while optimizing capacity utilization, based on the stored customer requirements.
Therefore,
Certain card management systems may rely on a manual pull and may lack capacity driven information and dynamic approach that adjust to changing customer conditions, e.g. demand increase or decrease, quality, machine or part shortages creating artificial load on a production cell (i.e., batch production environment), etc. In certain system cards may be shuffled daily and information may be dispersed through several different functional groups, and making decision making difficult for determining operator loading in each area. The scheduling wheel takes the pull inputs from planning and toads them on the wheel that acts as a tachometer to determine daily run rate for the cell. This information feeds the operator loading chart to determine standard work play. Based on inputs for the chart (cycle time, lead-time, backlog of work) an operator may determine the probability of taking care of the customer, and the system may provide a leading indicator of when and how many resources to add to a cell to meet customer demand. Certain embodiments may be used to measure machine time or operator time depending on capacity constraint for a particular resource.
The operations described in the figures may be implemented as a method, apparatus or computer program product using techniques to produce software, firmware, hardware, or any combination thereof. Additionally, certain embodiments may take the form of a computer program product embodied in one or more computer readable storage medium(s) having computer readable program code embodied therein.
A computer readable storage medium may include an electronic, magnetic, optical, electromagnetic, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. The computer readable storage medium may also comprise an electrical connection having one or more wires, a portable computer diskette or disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, etc. A computer readable storage medium may be any tangible medium that can contain, or store a program for use by or in connection with an instruction execution system, apparatus, or device.
A computer readable signal medium includes a propagated data signal with computer readable program code embodied therein. A computer readable signal medium may be any computer readable medium that is not a computer readable storage medium and that can communicate, propagate, or transport a program for use by or in connection with an instruction execution system, apparatus, or device. The computer readable storage medium is different from the computer readable signal medium.
Computer program code for carrying out operations for aspects of the present invention may be written in any combination of one or more programming languages.
Aspects of the present invention are described below with reference to flowchart illustrations and/or block diagrams of methods, system and computer program products according to certain embodiments At least certain operations that may have been illustrated in the figures show certain events occurring in a certain order. In alternative embodiments, certain operations may be performed in a different order, modified or removed. Additionally, operations may be added to the above described logic and still conform to the described embodiments. Further, operations described herein may occur sequentially or certain operations may be processed in parallel. Yet further, operations may be performed by a single processing unit or by distributed processing units. Computer program instructions can implement the blocks of the flowchart. These computer program instructions may be provided to a processor of a computer for execution.
The terms “an embodiment”, “embodiment”, “embodiments”, “the embodiment”, “the embodiments”, “one or more embodiments”, “some embodiments”, and “one embodiment” mean “one or more (but not all) embodiments of the present invention(s)” unless expressly specified otherwise.
The terms “including”, “comprising”, “having” and variations thereof mean “including but not limited to”, unless expressly specified otherwise.
The enumerated listing of items does not imply that any or all of the items are mutually exclusive, unless expressly specified otherwise.
The terms “a”, “an” and “the” mean “one or more”, unless expressly specified otherwise.
Devices that are in communication with each other need not be in continuous communication with each other, unless expressly specified otherwise. In addition, devices that are in communication with each other may communicate directly or indirectly through one or more intermediaries.
A description of an embodiment with several components in communication with each other does not imply that all such components are required. On the contrary a variety of optional components are described to illustrate the wide variety of possible embodiments.
When a single device or article is described herein, it will be readily apparent that more than one device/article (whether or not they cooperate) may be used in place of a single device/article. Similarly, where more than one device or article is described herein (whether or not they cooperate), it will be readily apparent that a single device/article may be used in place of the more than one device or article or a different number of devices/articles may be used instead of the shown number of devices or programs. The functionality and/or the features of a device may be alternatively embodied by one or more other devices which are not explicitly described as having such functionality/features.
The foregoing description of various embodiments of the invention has been presented for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. Many modifications and variations are possible in light of the above teaching. It is intended that the scope of the invention be limited not by this detailed description, but rather by the claims appended hereto. The above specification, examples and data provide a complete description of the manufacture and use of the composition of the invention. Since many embodiments of the invention can be made without departing from the spirit and scope of the invention, the invention resides in the claims hereinafter appended.