WIP management warehouse system

A WIP management warehouse is disclosed. It monitors and controls on-site materials in a warehouse center to avoid stocking materials for too long, and distributes materials to appropriate locators, thus simplifying the manufacturing process. The invention includes the steps of: establishing a stocking area, a picking area and a WIP management area; transferring materials in the stocking area to the picking area according to a WO for picking materials; transferring materials in the picking area to the WIP management area according to a KO for production; returning unused materials in the WIP management area to the picking area.

DETAILED DESCRIPTION OF THE INVENTION The specification discloses a warehouse system with an optimal management procedure in response to BPR (Business Process Reengineer) and ERP (Enterprise Resource Planning) proposed recently. Its goal is to reengineer the work procedure of warehousing to increase production while lowering organization operation costs. The invention is implemented in a warehouse system so that the inventory management, locator transfers, material distributing operations, material picking operations and the SFCS (Shop Floor Control System) in the warehouse system automatically retrieve data using an automated data capture method. Various kinds of optical and electronic scanning devices or bar code machines are employed to read data. The obtained data are updated in the system in real-time, avoiding possible problems due to time delays. A preferred embodiment is illustrated below to demonstrate explicitly how the disclosed method can be implemented. Through the warehouse management system, materials from different vendors are integrated and provided to the manager of assembly lines for easy management. Before a detailed explanation of the invention, let us first introduce the operation procedure of the invention and the picking method that defines a commodity hierarchy. Before the manufacturer ships any commodity, an ASN (Advance Shipping Notice) is first sent out. The BC (Bar Code) of each box of materials is scanned and the quantities are checked according to the ASN. The BC is used as an ID for each material. However, not all vendors can meet this requirement. In this case, those without an ASN will be provided with an ASN and any commodity without a BC will be given one. After scanning BC's, the system will sum up the quantities of different commodities according to the PO (Product Order) scanned. The scanned sum is then re-checked with the quantity indicated in a PL (Picking List). FIG. 1 - a shows a hierarchical relation diagram of commodity picking defined by the disclosed warehouse management system. It is used to define picking units in storage. Analyzing the data levels provided by the vendor, the top level should be ASN or the so-called cargo 10 . Below the cargo, there are several pallets 20 . Each pallet 20 is disposed with a plurality of material cartons 30 . Each material carton 30 contains materials of the same PO (Product Order) and the same type. Each material carton 30 has a plurality of material boxes 40 containing a plurality of material items 50 . A BC (Bar Code) label is attached to each unit as its ID. The above-mentioned BC's are linked together to form the ASN or data that should be included a standard shipping list. The disclosed warehouse management system provides a bin card, which can convert the ID consisting of BC's into a text description so that operators can obtain information relevant to the material during operations. The above-mentioned input data are obtained by scanning each BC using an RF (Radio Frequency) scanner. After a box of materials is shelved into the warehouse, the BC becomes the ID of the box. Data such as the locators in which the box has been placed, check-out quantities, persons who check them out, when the box arrived and which company the box belongs to are recorded on the ID for the warehouse management system to centralize its management. With reference to FIG. 1 - b , the hierarchical relation diagram is explained below. After counting all materials and scanning each BC, the RF scanner transmits the data to the warehouse management system in real-time. At that moment, the warehouse management system generates the hierarchical data as shown in FIG. 1 - b . A plurality of RT's (Receiving Ticket) 110 is then generated from a PL (Picking List) 100 . Within the same RT 110 , we can further group material cartons 40 with the same capacity of material items 50 into an SO (Storing Order) 120 . The SO 120 stores a plurality of locator addresses 130 , through which one can find the needed material carton ID's 150 and material item ID 150 from the BC's. With the complete BC management in the warehouse, the in and out or transfers of materials are immediately updated in the inventory database through the RF scanner, achieving real-time operations. Material distribution is a very complicated operation because different production methods have different requirements in picking. With reference to FIG. 2 , the warehouse management system provides a plurality of modules and a control mechanism for material distributing and picking operations. The warehouse management system 200 includes: a simulation module 210 , a reservation module 212 , a pre-reservation module 214 , a commitment module 216 , and a deduction module 218 . The five modules are prepared for the material distributing operation 230 . The goal is to solve the problems of normal material distributing operation. The five modules are explained in detail as follows: 1. Simulation module 210 : This module provides a simulation function, which prepares materials needed for assembly lines in the future according to a predetermined production schedule through the computation of the warehouse management system 200 . 2. Reservation module 212 : This module provides a reservation function, which reserves materials computed by the simulation module 210 so that the reserved materials will not be used by other units. 3. Pre-reservation module 214 : This module provides a pre-reservation function. Since the reservation module 212 only reserves the total quantity of materials, but not individual cartons, materials may be insufficient due to material deterioration. At this point, the pre-reservation module 214 automatically determines material shortage and performs pre-reservation. Once materials in shortage are received, the warehouse management system 200 then directly reserves the materials. 4. Commitment module 216 : This module provides a commitment function, which commits reserved materials to each carton of the materials for picking personnel to pick. 5. Deduction module 218 : This module provides a deduction function, which deducts picked materials from the reserved materials. FIG. 3 shows the structure of the disclosed SFCS (Shop Floor Control System). In this system, the stocking area is divided according to the characters and sizes of materials into a UL (Unit Load), an ML (Mini Load), an SML (Small Mini Load), and an SR (Strong Room). From small to large, there is a first area 310 , such as the SMT (Surface Mounting Technology), a second area 312 , such as the hand-plugging area, and a third area 314 , such as a system assembly area. The picking area can be divided according to the usage rate into a first KC (Kitting Center) 320 (such as a mother board KC) and a second KC 322 (such as an electronic KC). The assembly lines are also divided into WIP (Work In Progress) PW (Product Warehouse) materials 330 , WIP materials 332 , an OBS (Obsolescence) 340 and a component area 350 . FIG. 4 is a control operation flowchart of the disclosed SFCS. In step 400 , a stocking area, a picking area, and a WIP management area are established in the SFCS. Afterwards, the stocking area is divided into a plurality of different areas (step 410 ). The picking area is divided into a high usage rate KC and a low usage rate KC (step 412 ). The WIP management area is divided into a plurality of assembly lines (step 414 ). After the divisions are done, the SFCS can perform material picking, distributing and production. Through reservation via a WO (Work Order) and the demand in a client KO (Kit Order), the SFCS transfers each of the committed cartons of materials from the stocking area to the picking area (step 420 ). The materials in the picking area are then sent to the WIP management area (step 430 ). The materials can be sent from a high usage rate KC or a low usage rate KC. The materials stored in the low usage rate KC can be first used or separated into components (step 440 ). The materials with the highest priority for use can be immediately used for production (step 450 ). The materials separated into components are given to research centers, maintenance centers and units that need components (step 452 ). The high usage rate KC distributes materials only if all materials are ready through small WO's (step 400 ). In other words, the high usage rate KC does not distribute materials to the WIP management area until all materials needed in the WO are ready. Step 450 uses the materials on the assembly lines to make products. Unused materials in the WIP management area can be returned to the high usage rate KC or the low usage rate KC (step 460 ). The unused materials being returned to the high usage rate KC need to be put back to the stocking area regularly for future use (step 470 ). The unused materials being returned to the low usage rate KC are maintained by the KC (step 472 ). When unused materials are kept for too long, the system automatically determines whether they become dead materials (step 480 ). If they become dead materials, then they are returned to the OBS (step 490 ). If clients still need to use the unused materials, then step 440 follows to perform material usage and production in the low usage rate KC. The above-mentioned high usage rate KC, such as a mother board KC 320 , stores materials with high usage rates in order to save space. If any material has a slow flow rate, then it should be returned to the stocking area, preventing the KC from overstocking. The SMT area 310 , the hand plugging area 312 , and the system assembly area 314 have three different stocking areas to facilitate material distributing operations. The SR stores expensive materials such as CPU's and DRAM's. Therefore, it has a distinct material distributing operation and a person is assigned for material picking. When the system generates a PL for the SR, the assigned personnel can select the materials from the RF scanner and then use it to pick materials. Since the SR stores expensive materials, to avoid theft the material pallets and boxes are put away back to the SR after picking. They are moved to the locators for material distribution and to assembly lines only when the assigned personnel come to pick the materials. The locator transfers usually come from the demand of organizing locators. The warehouse management system first searches locators that contains cartons less than a predetermined quantity and combines them to form a list of locators for transfers. According to the list, material cartons in the locators are moved from a UL to an ML or the materials left in the material cartons in an ML are combined into new material cartons and then moved to an SML. The warehouse management system further provides an SKC (System KC). However, since the sizes of system materials are too big to be picked online or stacked in the KC, several picking stations are designed to be set at ASRS (Automated Storage Retrieval System) outlets (see FIG. 5 - a ). FIG. 5 - a shows the relation between the stocking area and the KC, and provides a preferred embodiment of the invention. The ASRS sends materials to each picking station 510 , 512 and 514 according to the different KO's (this process can be done using automated belts if space is available). Picking personnel at the picking stations then scans the BC's of material cartons 40 and determines quantities to pick. The rest of the materials are returned to the stocking area in ASRS ML 600 . When the KO's are all processed, there should be no stocks in the SKC. The only problem of this method is that it is not convenient for small-quantity and high-frequency picking because the ASRS and picking stations may be overloaded. If this production type is needed, the motherboard KC can be used. Another problem is that if the same carton is simultaneously committed by two KO's, then one of them may not be able to get the materials in time. A further exception is the SR in the SKC. The SKC is divided into two types: one being locators of the picking stations and the other being the SR. Therefore, one KO of the warehouse management system generates two PL's (one for the picking stations and the other for the SR). Thus, the ASRS UL and ML are divided into two areas. When there is one system KO committing, the warehouse management system will commit to the ID of each material carton. At the same time, the warehouse management system produces two KO's to get materials (in unit of cartons) from the UL and ML to the picking stations, respectively. When the material supply operation starts, the PL at the picking stations also starts picking operations. One PL corresponds to multiple KO's, and only one RF device is assigned to each KO to pick materials. Only one PL can be processed at a time. The materials left over from the picking at the picking stations are returned along with the material cartons back to the ASRS ML by assigned personnel. For each picking station, the system assigns a locator ID. The material supply personnel (or picking personnel) determine which picking station to supply (or pick) materials. With reference to FIG. 5 - b , in the KC 552 inside the picking area 550 , materials are disposed in PW's (Product Warehouses) 560 , 562 and 564 . Each PW has a plurality of assembly lines 570 , 572 and 574 . The warehouse management system manages the PW's so that each assembly line has PW locators. WO's (Work Orders) are listed individually for each of the assembly lines. Materials of different assembly lines cannot be shared. A safe stocking quantity is prepared for each material. When any material is stored below its safe stocking quantity, the warehouse management system automatically replenishes the materials. This material replenishment procedure is called the back flush operation, as described in FIG. 6 : First, when moving material, the ID on the material carton is scanned (step 600 ). From the scanning result, the system automatically deducts the quantity of the materials (step 610 ). The system then checks whether the quantity inside the PW is below the safe stocking quantity (step 620 ). If it is lower than the safe stocking quantity, then a location transfer request list is generated and given to a KC for picking materials (step 630 ). The picked materials are put into material cartons and transferred to the PW locators (step 640 ). If the quantity of the material is not lower than the safe stocking quantity, step 650 follows directly. After a product is finished, its ID is scanned (step 650 ). The materials in the product are deducted from the inventory and transferred to the product (step 660 ). The location transfer request list generation cycle time is set by the warehouse management system. The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.