The present application claims priority to Japanese Patent Application No. 2018-044893, filed Mar. 13, 2018. The contents of this application are incorporated herein by reference in their entirety.
The present invention relates to a system for planning where to place merchandise items and a method for planning where to place merchandise items in a distribution warehouse to support designing a warehouse and work therein.
In physical distribution, between manufacturing sites and retailers or consumers, a distribution warehouse is established to receive products from multiple manufacturing sites and select and ship required merchandise items to multiple retailers or multiple consumers in the case of mail-order or online shopping transactions and the like. Also, in some situations, a physical distribution management system may be introduced to perform handling such as giving instructions for actual shipment work and placing orders based on order details from retailers or consumers.
Recently, small-quantity and wide-variety merchandise items have become to be handled in a distribution warehouse, whereas bounded delivery time from order to delivery has become very short. Therefore, it is required to make warehouse operations efficient with limited working personnel and in a limited warehouse area. Actually required working hours differ according to the layout of shelves and passages inside a warehouse, a method of placing merchandise items on the shelves, and a sequence of performing shipment work among others and, therefore, it is needed to design to implement these operations efficiently.
For instance, it is known that, even for a warehouse that handles a great quantity of merchandise items, hot-selling items are usually about 20% of the total of merchandise items and account for 80% of the entire shipment amount. Meanwhile, inside a warehouse, for items being in a place that is near to a doorway of the warehouse, their moving distance for shipment is short and time it takes to collect items for shipment can be reduced. In consideration of these matters, in Patent Literature 1, disclosed is an invention that creates a past shipment ranking from past shipment records and presents a placement plan of placing top 20%, high-ranking merchandise items as near a warehouse doorway as possible.
In an operating distribution warehouse, however, working hours for changing the placement of merchandize items (merchandise item placement change working hours) arise, differently from an initial design of the distribution warehouse, according to the number of merchandize items relocated. Hence, in consequence of changing the placement of merchandise items, even when working hours for shipment have been reduced, when a large quantity of merchandise item placement change working hours arises, the effect of reducing total working hours by summing up both may decrease or go negative in some situations. Therefore, there was a need to present an optimum placement of merchandise items taking account of cost related to changing the placement of merchandise items, not only reducing the working hours for shipment.
In addition, the shipment amount and the shipment ranking changes in time series. Even in a system disclosed in Patent Literature 1, a user is allowed to change the placement of merchandise items appropriately. But, because changing the placement of merchandise items also generates cost, it is not necessarily efficient to move high-ranking items in the shipment ranking to a location where items are easy to pick, following this shipment ranking in each case. Therefore, there was a need to present an optimum placement of merchandise items based on an effective period of the placement of merchandise items once performed and prediction as to how the shipment ranking will vary for that period.
Moreover, in predicting the working hours of shipment work and merchandise item placement change work, a variation arises due to an uncontrollable external factor such as a worker's attribute and an actual work rate. Therefore, there was a need to determine an effect-to-cost ratio including this variation and present placement plans of merchandise items depending on tolerance of variation in work, allowing a user to make a choice. When a warehouse is operating with its handling capability nearly reaching its limit, for example, in busy time, a smaller variation that is predicted is favorable, even though the ratio of the effect of reducing the working hours for shipment to the merchandise item placement change working hours is rather low, as compared with a case where the effect-to-cost ratio is high, but the variation is large. This is because a large variation could result in a risk that shipment work does not finish by the time limit of shipment, as the effect of reducing the working hours for shipment becomes less than an average to a large extent according to circumstances and the handling capability of the warehouse is exceeded. On the other hand, in a quiet season, it is desired that a plan in which more effect can be expected, even though the variation is large, can be chosen.
A system for planning where to place merchandise items in a distribution warehouse, pertaining to the present invention, is characterized by including: a merchandise item placement change creation unit which creates a placement change plan of merchandise items based on merchandise item placement data inside a distribution warehouse; a work plan creation unit which creates first virtual work instruction data reflecting a shipment frequency prediction of merchandise items on work instruction data relevant to past shipment of merchandise items and second virtual work instruction data with placement of merchandise items reflecting a placement change plan of merchandise items; a shipment working hours prediction unit which calculates a predicted value of reduction in shipment working hours based on prediction of the shipment working hours with respect to each of the first virtual work instruction data and the second virtual work instruction data; a placement change working hours prediction unit which calculates placement change working hours to perform a placement change plan of merchandise items; and a control unit which subtracts the placement change working hours from the predicted value of reduction in shipment working hours, thus obtaining a difference, and determines to adopt a placement change plan of merchandise items if the difference fulfills a condition of being at or above a certain threshold which is positive or determines to review the placement change plan of merchandise items unless fulfilling the condition.
According to the present invention, it would become possible to present optimum placement plans of merchandise items taking account of working hours to perform placement change of merchandise items and shipment frequency of each merchandise item changing over time, in addition to shipment working hours, and allow a user to makes a choice. Moreover, a user is allowed to choose an optimum placement plan of merchandise depending on tolerance of variation in prediction items.
Embodiments for carrying out the invention will be described below with the aid of the drawings.
The system 101 for planning where to place merchandise items is comprised of a CPU 102 and a memory device 103 and is connected with a user terminal 100 through a network 109. The system 101 for planning where to place merchandise items runs as a program residing in the memory device 103, but a limitation to this configuration is not necessarily intended for example, a part of the system may be implemented by dedicated circuits.
Storage equipment 104 is also connected to the system 101 for planning where to place merchandise items. In the storage equipment 104, work record data 105, merchandise item placement data 106, work instruction data 107, and merchandise item characteristic data 108 are stored. In
The system 101 for planning where to place merchandise items is comprised of a control unit 110 which executes a process of planning where to place merchandise items in response to input/output from a user, an optimization unit 120 which performs optimizing a placement plan of merchandise items, and a working hours model creation unit 130 which creates working hours models 140 for use in the optimization. Also, the system internally retains optimization parameters 141 accepted from a user and predicted values of shipment frequency 142 in addition to the foregoing working hours models 140.
The optimization unit 120 is comprised of a work plan creation unit 121, a shipment working hours prediction unit 122, a merchandise item placement change creation unit 123, and a placement change working hours prediction unit 124.
The working hours model creation unit 130 creates in advance a working hours model 140 from the past work record data 105, merchandise item placement data 106, work instruction data 107, and merchandise item characteristic data 108, as presented in
In addition, a working hours model 140 may be created through approximation which is performed in advance using a method, such as, e.g., regression analysis with regard to the following data: a worker's moving distance and the number and quantity of merchandise items to pick which will result when a worker will perform work details described in the work instruction data 107; values of, inter alia, weight and size of merchandise items recorded in the merchandise item characteristic data 108, and a value of working hours it takes to perform work as specified by the work instruction recorded in the work record data 105. Moreover, a method based on simulation may be adopted to obtain prediction with a higher accuracy than this working hours prediction.
Multiple shelves are arrayed inside a distribution warehouse and merchandise items can be shelved on and taken out from a shelf from a passage that the shelf faces. As depicted in
Merchandise items that are treated in a distribution warehouse are assigned merchandise item codes and, for each merchandise item, the merchandise item code of the merchandize item, a location code denoting a location where the merchandise item is shelved, and a quantity of pieces of the merchandise item shelved are managed as the merchandise item placement data 106. By way of example of the merchandise item placement data 106 as presented in
In the present embodiment, units that are managed with the merchandise item placement data 106 can uniquely be identified by merchandise item code; however, in some warehouses, even the same merchandise item, but with differing production lots or expiration dates among others, may be regarded as different ones and such item may have to be differentiated in management. In that case, the merchandise item placement data is also modified to manage production lot or expiration date as well in addition to merchandise item code.
The work instruction data 107 is created to represent details of work instructions in a distribution warehouse depending on order details from retailers or consumers among others. Practically, shipment work is divided per shipment destination or shipment destination group and one worker usually performs one part of shipment work.
As represented in the example as presented in
A worker performs shipment work sequentially based on work instruction data 107 as presented in
In the example as presented in
When making a plan for changing the placement of merchandise items, the control unit 110 (
As a first step, the control unit 110 accepts optimization parameters from a user.
The user inputs optimization parameters using an optimization parameter input screen.
An input screen depicted as “Example 1” in
An input screen depicted as “Example 2” in
The control unit creates a shipment ranking from the work record data 105. Using the work record data 105, e.g., for the last one week or the last one month, a shipment ranking can be determined by summing up the number of lines of data and the merchandise item quantity per merchandise code described in the work record data 105. The control unit 110 displays merchandise items ranked according to the shipment ranking in a shipment frequency prediction input screen which is depicted in
The control unit 110 accepts input of a shipment frequency prediction (a tendency for the optimization period) from the user as a tendency of shipment frequency for the period subject to optimization for each of the merchandise items (merchandise item codes) displayed on the shipment frequency prediction input screen. For example, for “detergent A” which is rank 1 of shipment frequency ranking, if the user predicts that the shipment frequency will go constant, as compared with past records based on past statistics or the like, the user would enter a string “constant”. For other merchandise items (merchandise item codes), if their shipment frequency for the period subject to optimization is predicted to increase or decrease, the user can enter a string “increase” or “decrease” including how much it will increase or decrease (e.g., “10%” as in the relevant drawing). Now, because this entry (a tendency for the optimization period) is purely a predicted value, an additional field allowing entry of a degree of certainty, variation, etc. may be provided. Additionally, by referring to the work record data 105 for the corresponding period in the preceding year (checking a checkbox “Use records in the preceding year as presented in
The merchandise item placement change creation unit 123 selects merchandise items from the merchandise item placement data 160 and creates a placement change plan of merchandise items in which location code exchanging is done among a group of selected merchandise items.
The work plan creation unit 121 creates virtual work plan data based on past work instruction data 107 and the shipment frequency prediction accepted at step 703 (S703).
Here, one example of a method for creating virtual work instruction data as a virtual work plan is described.
In one example as presented in
Furthermore, when a placement change plan of merchandise items is given, it has an effect of shipment work. In fact, when placement of merchandise items is changed, the locations of the respective merchandise items to be picked, described in work instruction data 107, are changed. However, because a sequential order of picking is defined for the locations, the sequential order of picking may be reversed when the locations are changed.
For instance, let us suppose that a placement change plan was given in which, as for a merchandise item with merchandise item code “13275” placed on a shelf specified by location code “02-01-02” and a merchandise item with merchandise item code “69163” placed on a shelf specified by location code “01-02-01”, their shelved locations should be exchanged (see the work instruction data 107 as presented in
Moreover, exchanging of data in lines occurs in relation to the sequential order of picking, as presented in “(d) after applying placement change” in
But, a route of picking is defined, as presented in “(a) plan view inside warehouse” under physical placement inside warehouse in
Through the procedure as described above, virtual work instruction data reflecting the shipment frequency prediction and virtual work instruction data with the placement of merchandise items reflecting the placement change plan are created.
The shipment working hours prediction unit 122 calculates a predicted value of reduction in shipment working hours. A predicted value of reduction in shipment working hours is obtained by applying the virtual work plan (virtual work instruction data) created at the foregoing step 705 (S705) to the working hours model 140 which was previously created by the working hours model creation unit 130 based on past work record data 105. That is, for each of the virtual work instruction data reflecting the shipment frequency prediction made from the past work instruction data 107 and the virtual work instruction data with the placement of merchandise items reflecting the placement change plan of merchandise items, shipment working hours are predicted using a prediction model of shipment working hours. From the predicted values of shipment working hours for each of the former and latter ones of virtual work instruction data, a predicted value of reduction in shipment working hours is calculated.
The placement change working hours prediction unit 124 calculates placement change working hours. The placement change working hours are determined from a product of multiplying the time for placement change per merchandise item, which was input by the user as an optimization parameter at the foregoing step 701 (S701) by the number of merchandise items to change placement in the placement change plan created at step 704 (S704).
Additionally, measures for improving the accuracy of determining the placement change working hours can be taken. As one of the measures for improving same, placement change working hours per merchandise item may be determined by using an average of such working hours obtained from data recorded when placement change work was performed in the past (placement change record data). Furthermore, as another one of the measures for improving same, the following method may be adopted. Time for placement change per merchandise item is actually determined depending on variables such as distance to move a merchandise item for its placement change, amount of stock, and weight and size of a merchandise item. Therefore, these variables that have an effect on the time for placement change are derived using merchandise item placement data 106 and merchandise item characteristic data 108. After that, an approximation formula for calculating the time for placement change based on the placement change record data, taking account of derived variables, is determined in advance and stored in the working hours model 140. When calculating the total time for placement change, a calculation is performed using this approximation formula.
The control unit 110 compares the predicted value of reduction in shipment working hours with the placement change working hours calculated through the foregoing steps 704 (S704) to 707 (S707) and determines whether or not cost-effectiveness is at or above a certain level. Specifically, if the placement change working hours are subtracted from the predicted value of reduction in shipment working hours and the thus obtained difference is a positive value (Yes), the placement change plan is adopted; if not so (No), the procedure returns to step 704 (S704) to review and recreate a placement change plan. In addition, as a criterion of determination, instead of a positive value obtained as the difference between the predicted value of reduction in shipment working hours and the placement change working hours, the user may be prompted to set a threshold of the difference in advance and the placement change plan, if it is at or above the threshold, may be adopted.
The control unit 110 outputs a placement change plan and a cost-effectiveness graph obtained from the placement change plan to the user terminal 100 to present the adopted placement change plan to the user. Furthermore, the system may develop multiple placement plans, collect a certain number of placement change plans, and output the plans in descending order of cost-effectiveness to provide room for choice so that the user can choose an appropriate placement change plan according to circumstances or the like.
For multiple placement change plans collected at the foregoing step 709 (S709), this screen displays a ratio of the effect of each plan and in addition, also displays a predicted value of reduction in shipment working hours (time of reduction in shipment work), which corresponds to the effect, and placement change working hours, which correspond to cost, based on both of which the ratio of effect is determined.
When this variation element is added, a variation that is determined derivatively from the variation element arise in a ratio of effect, placement change working hours, and time of reduction in shipment work; therefore, a range of this variation may be displayed additionally.
This presents output details of placement change plans 1 and 2 among the placement change plans 1 to 3 as presented in
In addition, in
Furthermore, because cost and effect are purely predicted values, it is supposed that variation arises in the predicted value, inter alia, if the accuracy of prediction is not sufficiently high or if an indeterminable element is included. In
Number | Date | Country | Kind |
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2018-044893 | Mar 2018 | JP | national |