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WMS Computer Order Pool In a warehouse using a WMS program, the host computer receives orders, verifies that the specified SKU is available for sale, and performs necessary activities, and forwards the orders to the WMS computer. In the WMS computer, new customer orders from the host computer and existing customer orders make up an order pool. Still in the WMS computer, a customer order pool is sent to a warehouse staff for a warehouse order wave creation plan (customer order quantity that is planned for warehouse order pick activity completion within a work day). Based on a warehouse order wave, a WMS computer allocates order wave SKU quantity for an order wave pick activity and sends SKU move transaction messages to the warehouse. After the warehouse staff creates an order wave in the WMS computer, a WMS computer with a customer order wave or planned to work orders depletes the customer order wave orders from the order pool. If a warehouse order wave has an order quantity less than the WMS computer order pool quantity, the WMS computer has an existing customer order pool quantity that is available for a warehouse next work day/order wave. If a warehouse created order wave quantity is equal to the WMS computer order pool quantity, the WMS computer has a zero customer order pool quantity for a warehouse next work day/order wave. ---------------
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------------ Order-Wave Creation Each warehouse establishes an allocation priority as part of the order wave. To make an order wave for a warehouse pick design, based on an order number, customer order SKU quantity and ware house budgeted employee productivity rates, a warehouse wave planner adds each customer order wave component to the base until a total customer order wave customer order number and customer order SKU quantity equal to an employee number and budgeted employee productivity. If the number of orders and the quantities ordered exceed the warehouse employee budgeted time and productivity, the pick design can carry over the order base to the next work day or order wave. Examples of order wave components are: -- Customer order age or date host computer received the order -- Express orders -- Orders for special or promotion SKUs -- Single-line single SKU orders -- Single-line multiple SKU orders -- Multi-line multi-piece -- SKU group combination -- Special handling -- By shipper -- Distinguish between different countries your operation has to deliver through different customs and pick-up for different country deliver -- Other company criteria Order-Wave Planning An order wave is the maximum number of orders out of a given order pool that a warehouse can effectively and efficiently handle within a given time period. It is based on predetermined operational parameters (e.g., employee productivity, existing customer order carry-over and company carry-over procedures, customer order age, express customer order, customer order carton size, or zip code). For example, the time periods are the predetermined work-day hours. The number of orders waves per work-day may have a minimum of one or be defined by other parameters. Some warehouses are designed to receive orders every two hours or at specific time slots, which are then sent to warehouse staff to create an order wave. After the warehouse staff creates an order wave in the WMS computer, the computer allocates SKUs transactions from storage positions to pick positions. After the computer is notified that SKUs have been scanned at a position, the computer releases the order wave to the pick area. Warehouse order wave plan options are: -- Warehouse area -- SKU or SKU type -- Warehouse pick zone -- Date received for FIFO rotation -- Manufacturer lot number -- Priority customer -- Express shipper -- Carrier or delivery company -- Postal zip code -- Shipping-carton size -- Order type (e.g., single-line/single SKU, single-line/multiple SKUs, multi-line with single or multiple SKUs, combi or multiple SKU group, COD, or credit or cash). Order-Wave Characteristics An order wave may be fixed or continuous, as determined by the design team. Continuous Order Wave Flow A continuous customer order wave is basically a nonstop order wave in which the WMS computer provides orders on a continuous flow to the warehouse. In a warehouse using a continuous flow design does not allow for an opportunity to profile, clean up, or reorganize pick positions. A continuous flow approach has customer order Wave 1 or Work Day 1 in a pick zone "C" SKU movers are adjacent to customer order Wave 2 or Day 2 "A" SKU movers. This SKU arrangement creates lower picker productivity due to increased walk distance between two picks. To assure "A" SKU movers are in adjacent pick positions you pick clean pick positions with a residual "C" moving SKU inventory. This approach requires minimal labor to reorganize a pick line, and additional time to profile a pick line. Fixed Order Wave Flow In a fixed order wave flow, the WMS computer groups orders with predetermined customer order numbers. An order wave number is based on order wave parameters (e.g., employee productivity, customer order age). In a fixed flow design, the warehouse is expected to complete all orders (or order waves) within a predetermined time period as well as pick-line clean-up or reorganization. Order Wave: Ensuring Optimal Warehouse Performance One of the objectives of an order fulfillment warehouse with a WMS program is to provide accurate customer service within an order/delivery cycle time period and at the company's desired cost per unit. The five steps for achieving this objectives are: 1. Complete order wave size activity, which determines the number of orders per wave; 2. Determine the number of orders per wave and what customer order types are included in an order wave; 3. SKU handling; 4. Order processing (i.e., pick, pack, manifest, and ship orders); and 5. Cleaning and/or reorganization of pick positions. Order Numbers and Totes In a warehouse with a WMS program using a warehouse tote as an order tote, a picker transfers picked SKUs from a pick position into the tote. The tote is moved to the check/pack station. The objectives of using a tote are: -- It provides a secure in-house container that ensures that picked SKUs arrive at the next warehouse activity station; -- It provides an exterior surface that permits bar-code scanner or RF tag reader to receive a signal from the tote identification; -- It is designed with features that permit an employee (or machine) to handle an empty or full tote and transfer picked SKUs between a tote and employee (or machine) pick position or work station. A warehouse tote is manufactured from hardened plastic, corrugated plastic, or corrugated cardboard. The tote's exterior dimensions match the warehouse's pick/pack transport design; the interior dimensions are designed to hold SKUs. As a tote enters the warehouse pick design, the tote's identification travels past a bar-code/RF tag reader, which sends the identification to the warehouse computer. The warehouse computer associates the tote identification with one or more orders. This association permits the warehouse to complete order pick, check, weigh, and pack transactions. The design team may create a design with one order per tote or multiple orders. (If the warehouse uses totes as order delivery containers, one customer order per tote is preferred.) ------------------------
-------------------------- Multiple Orders per Tote As a tote enters a warehouse pick line, a bar-code scanner/RF tag reader sends the tote identification to the warehouse computer. The computer associates two or more orders with the tote. As the tote moves through a pick design, the picker (or pick machine) is instructed to pick (or release) an order for two or more SKUs from a pick position into the tote. This approach features -- Fewer pick tote numbers on a warehouse pick or in-house transport design; -- Order pick instructions are for two or more or multiple SKU orders; -- Increased manual picker pick errors; -- A larger pack station; -- At a pack station, for a packer to complete a quantity picked SKU check activity with a pre printed or printed on-demand customer order packing slip or a PC (personal computer) to flip or show multiple customer order packing slips has -- Potential pack errors; -- A more complex WMS program or warehouse computer program is necessary to group multiple orders in one tote and to ensure accurate packing slip presentation. One Order per Tote In this design, the tote enters the pick line and a bar-code scanner/RF tag reader sends the tote identification to a warehouse computer. The warehouse computer associates one customer order with the tote. As the tote moves through the pick design, the picker (or pick machine) is directed to pick (or release) a SKU from a pick position into the tote. This approach features: -- More totes on the in-house transport. With a high-volume operation, this could require a second pick line or shift; -- Faster conveyor speeds or a second warehouse shift; -- Simple pick instructions; -- Fewer manual picker errors; -- Simple pack station activity and a smaller pack table; -- It uses a SKU picked quantity pick check activity; -- Fewer pack errors; -- Less complex computer program. Order Identification Sequence After a warehouse with a WMS program design team has determined that each customer order uses either a host or WMS computer customer order identification or associate a host or WMS computer customer order identification to a warehouse customer order identification, the design team next customer order identification option is to determine customer order identification sequence. Customer order identification sequence either use a host or WMS computer customer order identification or warehouse operation customer order identification. The purposes of customer order are to 1) permit the host computer customer order identification to uniquely or discreetly identify one customer order from other customer orders that allows customer order recorded and tracked in a company; 2) to associate a customer order identification with customer order SKUs or pieces; 3) to ensure that SKUs are picked and assembled to comply with a customer order; and 4) to have a simple customer order identification pick and check activities that has each customer order identified tote/carton progressively move past pick positions. Customer order identification sequence options are: 1. A random generated number that has a host or WMS computer program refer to a random number file. A random number file is created by a computer and each number printed onto a customer order identification label is discreet. A discreet number is required to uniquely identify each customer order identification in an order fulfillment operation. A random number generated four customer order identification (e.g., 101010, 239499, 728549, 066837); 2. A random number generated customer order identification approach has a large number quantity, requires a separate computer program, customer order identification requires an alpha characters or numeric digits that uniquely identifies each customer order and difficult to have customer order identifications that have an arithmetic or orderly progression. To pro vide a customer order identification with a Julian date and random generated number, each customer order identification required front digits are random generated numbers that are printed as a customer order identification number. As required by a host or WMS computer program customer order identification digit number, zeros are added or printed onto a label face. Each customer order identification is a generated number (e.g., January 10, 2006 with four customer order identifications = 1106010, 0206010, 2306010, 4006010); 3. A Julian date with a random number generated customer order identification approach has a large number quantity, requires a separate computer program, customer order identification requires numeric digits that uniquely identifies each customer order and customer order identifications that have an arithmetic or orderly progression Julian date and lowest number uses a Julian date and number arithmetic sequence. If required to create a number for each year, two additional digits are used to identify the year (e.g., for January 10, 2006, the first customer order identification = 06010; the second customer order identification = 06011). To provide a customer order identification, as each customer order identification is printed, the next customer order identification number is increased by one. As required by a host or WMS computer program customer order identification digit number, zeros are added or printed onto the label face. Each customer order identification is a generated number (e.g., for January 10, 2006 with four customer order identifications = 06010, 06011, 06012, 06013). A Julian date with a random number generated customer order identification approach has a large number quantity, requires a separate computer program, customer order identification requires numeric digits that uniquely identifies each customer order and customer order identifications that have an arithmetic or orderly progression; 4. Arithmetic progression from lowest number that is sequenced by a lowest number has a host or WMS computer program that prints each customer order identification number from a lowest number to a highest number. With sufficient digit or number positions, the first customer order identification number starts with "1" and each customer order identification number is increased by one. With this customer order identification print sequence, each number printed onto a customer order identification label is discreet. Discreet numbers uniquely identify each customer order in an order fulfillment design (e.g., 000001, 000002, 000003, 000004). An arithmetic number progression from a lowest numbered customer order identification approach has a unlimited number quantity, separate computer program, customer order identification uses alpha characters or numeric digits that uniquely identifies each customer order and customer order identifications that have an arithmetic progression. In-House Transport The SKU's identification is a signal to the in-house transport that the SKU is ready to be moved to a storage position. The in-house transport (manual or automatic) moves the SKU from the receiving dock to a drop point/location or storage position. With automatic transport, bar-code scanners/RF tag readers along the transport path update the computer as the SKU travels to the drop point/location or storage position. Depositing an Identification SKU into a Position When a SKU is on the in-house transport carrier surface, an employee, employee controlled fork lift or AS/RS crane travels to a vacate storage position. Again, each inbound SKU travels past a bar code scanner/RF tag reader that updates the SKU's movement. All inbound SKUs travel past a size and weight station to verify that each SKU's physical characteristics match design parameters. In an employee directed SKU put-away/deposit design, an employee randomly selects a storage position. A forklift truck driver scans the SKU identification and storage position. Scan transactions are sent to the WMS computer, which updates the inventory. In a warehouse using an AS/ RS crane or computer-directed storage deposit design, the storage strategy determines the storage position, the AS/RS crane design communicates the completion of a storage transaction; the WMS computer updates inventory files regarding the SKU and it's position. SKU Storage Transaction Files: Entry and Storage As a warehouse employee, employee-controlled forklift truck, or an AS/RS crane completes a pal let, master carton or single SKU put-away transaction, the SKU and storage/pick position identifications are scanned (with a quantity) and sent to the computer. The SKU quantity and position status is updated in WMS inventory files. In WMS inventory files and especially for a dated SKU that requires a FIFO rotation, with a vendor delivery and customer order returns for one SKU, a WMS program tracks an oldest SKU as next SKU picked for a customer order. The file entry options (by SKU) are: -- With a lowest identification number as an oldest SKU transaction completed and entered into the WMS inventory storage files. The WMS computer uses a SKU identification label number to determine the oldest SKU. The lowest SKU number is identified as the oldest SKU in the inventory files. To have an effective SKU age in the inventory files, the SKU identification uses (a) Julian date with a progressive SKU identification number, (b) progressive SKU identification number, or (c) random SKU identification number, but a date is entered with an identification number into the inventory files; -- A SKU identification number is created when SKU is unloaded/received from a vendor delivery truck. A receiving clerk places an identification label onto each SKU. An employee controlled forklift truck completes the deposit transaction by placing the SKU into a storage position and scanning the identification and storage position. The scans and SKU quantity are sent to the WMS computer, which updates the SKU storage position status in the inventory files; -- By a SKU put-away transaction sequence as the first SKU transaction completed and entered into the inventory files as the oldest SKU. The forklift truck driver scans a SKU identification, places the SKU into a storage position, and then scans the storage position. The scan transactions and SKU quantities are sent to the WMS computer. The computer updates the SKU storage position status in the inventory files. Storage Area Reorganization Strategies For a warehouse designed to use a forklift truck or AS/RS with cartons or pallets, with a one- or two-shift order fulfillment operation, and advanced order SKU demand knowledge (i.e., host computer transfer SKU demand), there are several possible SKU reorganization strategies. Warehouse reorganization occurs off-shift. The WMS computer directs the forklift trucks or AS/RS cranes to move a SKU from one storage position to another. (Scans and SKU quantities are updated in WMS computer files.) The design team SKU reorganization strategy is focused on high-volume. During low volume time periods, there is an opportunity to reorganize obsolete ("C" or "D") SKUs or noncustomer-order related SKUs. In a reorganization strategy, priority warehouse positions are located at a storage aisle first position to a position that is three-quarters from the first position or aisle front. The reorganization strategy for high-volume SKUs is built around a put-away strategy to have SKUs remain in existing storage positions. In this strategy, the warehouse forklift truck or AS/ RS crane completes a deposit transaction to the storage position. During an off-shift, the SKU remains in the initial storage position. Upon receipt of an order, the computer directs the ware house to move the SKU to another storage position. The SKU identification and new storage position are sent to the computer for update. This approach means quicker travel time from the storage position to the P/D station. For high-volume SKUs in a warehouse where only one aisle has a high SKU quantity, the reorganization strategy option is to spread SKUs to other aisles during off shifts. The first step is to make the initial SKU deposit transaction to a vacant storage position. The host computer and management team will have estimated (or has exact) SKU sales volume (this occurs during a nonproductive shift). Based on projected sales data, the WMS computer and warehouse reviews SKUs storage positions in each aisle. If there is a high number of SKU transactions in one aisle, the WMS computer directs the warehouse move SKU transactions to aisles with fewer transactions. A SKU relocation or move transaction to an aisle, the WMS and warehouse computers ensure that anticipated AS/RS crane SKU withdrawal transactions for customer orders per aisle are within an AS/RS crane design transaction number. The option is for high-volume SKUs in warehouses with preplanned vacant storage positions in aisle front storage positions. To move high-volume SKUs from an initial deposit aisle (middle or rear) position to an aisle vacant front storage position, there are three steps. 1. During a regular put-away activity, the WMS computer keeps the front two or three storage positions in each aisle vacant. 2. The WMS computer directs the employees to deposit high-volume SKUs to vacant storage positions. 3. During a nonproductive shift, the WMS computer has estimated sales volume for high-volume SKUs. Based on the projected sales data, the WMS computer sends a message to a ware house to direct each aisle AS/RS crane of forklift truck to complete SKU move or relocation transaction. Each SKU move transaction moves an order wave (or next work day high-volume SKU) from an initial storage position to vacant front two or three storage positions. When compared to other reorganization strategies, this approach decreases a forklift truck or AS/RS crane travel time and increases the number of AS/RS crane storage transactions. For "C" or "D" SKUs or noncustomer-order related SKUs with preplanned vacant storage positions from a rear aisle to a three-quarter aisle, the reorganization design has three steps. 1. During a regular put-away activity, a WMS program and warehouse computer in each aisle keeps an aisle last three-quarter positions vacant. 2. The WMS computer directs "C" or "D" SKUs or noncustomer-order related SKUs to be deposited in vacant storage positions. 3. On a nonproductive shift, the WMS computer has estimated "C" or "D" moving SKUs or noncustomer-order related SKUs. Based on the projected sales data, the WMS computer sends a message to the warehouse to direct each aisle AS/RS crane of forklift truck to complete the move or relocation transaction. Each transaction moves "C" or "D" SKUs or noncustomer-order related SKUs from an initial storage position to an aisle last three-quarter vacant positions. Having 'A' moving SKUs in an aisle front positions, decreases forklift truck or AS/RS crane travel time and increases the number of storage transactions. SKU Rotation SKU rotation is dictated by the SKU life cycle. The purchase department and the vendor indicate the SKUs that require a specific rotation. There are two SKU rotation options. First, there is a FIFO rotation. In a SKU FIFO (First-In, First-Out) rotation design, a SKU that is received first in the warehouse is withdrawn first from the inventory or storage position. A FIFO rotation indicates that a SKU has a predetermined life (or time limit) before it spoils. After a specific date and if a SKU is not withdrawn from a storage position for orders, the SKU is placed in a "not available for sale" status. As each SKU is received into a warehouse, it is given a date entered that is entered into the inventory. As the computer receives orders for a SKU, the computer directs that the oldest SKU is withdrawn first. Second, there is a LIFO (Last In, First Out) SKU rotation. A SKU that is received last is with drawn first from inventory or a storage position. A LIFO SKU does not have a specific shelf life and does not require a WMS computer to track the age of the SKUs. Manufacturer Lot Numbers A SKU manufacturer lot number is dictated by SKU type and the company's desire to track specific SKUs. The purchasing department and vendor ensure that each SKU has a manufacturer lot number. As a SKU is received at a facility and receives an identification, a manufacturer lot number is entered as part of the identification. If there is manufacturer recall or "stop sell" notice for a SKU, the computer lot number ensures accurate access to a SKU that potentially requires additional positions. If the warehouse needs to register a customer who has received a lot or serial number, it is a complex process that requires a complex computer program. SKU-Identification Sequence in the Inventory Files After a receiving clerk attaches an identification to a SKU, a clerk scans the SKU identification, enters a quantity into the computer inventory files, and sends the data to the computer. The computer files associate the SKU with a quantity and tracks the identifier and quantity as it flows through the storage/pick design. With a SKU that has a shelf life or has a FIFO, lot, or serial number rotation, the data ensures proper rotation and the computer ensures that the forklift truck or AS/RS crane has access to an assigned SKU. The withdrawal sequence options are by: 1. Oldest SKU as a first identification label scanned at the receiving dock. 2. Lowest SKU identification number. 3. Julian date and lowest identification number. SKU Storage Characteristics SKU physical characteristics determine environmental SKU storage characteristics. Physical storage characteristics include pallet, master carton, single pieces in a tote or container, temperature sensitive, high value, toxic, edible, hazardous, and flammable. The design team ensures that each SKU is assigned to its proper storage position within a warehouse storage area or aisle. To assist in a proper SKU movement from the receiving dock to the proper storage area, each storage area is included in the WMS SKU identification. SKU Put-Away/Deposit Strategies or Philosophies The warehouse's put-away or deposit strategy, storage philosophy, or principle for positions are factors that determine transaction equipment and storage positions in the warehouse. The warehouse storage area is an important area in a facility. It occupies the largest area (square feet) and contains the highest inventory value. SKU deposit strategy or storage philosophy options are SKU popularity or Pareto's Law (The 80/20 rule) ABC theory unload-and-load ratio round-robin family group or kit pallet, carton, or GOH height temperature sensitive security toxic and nonedible flammable power in one aisle power to the front SKU inventory digit number SKU rotation SKU Popularity-Pareto's Law (The 80/20 Rule) A warehouse storage design based on a SKU popularity has a SKU allocation to a storage position derived from Pareto's Law (after Vifredo Pareto, an Italian economist, 1848-1923). This law states that 80% of the wealth is held by 20% of the people. In the storage/pick industry, 80% of the volume shipped to customers is derived from 20% of the SKUs. Many studies have indicated that another 10% of the volume shipped to customers results from another 30% of the SKUs and that an additional 5% of the volume shipped to customers can be attributed to 55% of the SKUs. In recent studies, the results show that 95% of the volume shipped to customers is obtained from 55% of the SKUs. This is referred to as "Pareto's Law revisited." ABC Theory When a warehouse professional refers to the three zones of Pareto's Law, this refers to the ABC theory. The ABC theory states that "A" storage/pick zone positions have fast-moving SKUs deposited to aisle storage/pick positions. These SKUs are few in number and have a large inventory quantity per SKU. "B" storage/pick zone positions have medium-moving SKUs deposited to aisle storage/pick positions. These SKUs are medium in number and have a medium inventory quantity per SKU. "C" storage/pick zone positions have slow-moving SKUs deposited to aisle storage/pick positions. "C" SKUs are large in number and have a small inventory quantity per SKU. An ABC theory increases SKU hit concentration (the SKU number that appears on an order group) and density (the number of SKUs per customer order line per aisle) and minimizes the travel time necessary for storage transaction, which is particularly useful for warehouses using AS/RS storage, employee controlled forklift truck, or manual designs. If a warehouse has receiving and shipping docks on the front side of the facility, and SKU storage position allocation is based on a ABC theory, "A" SKUs are allocated to storage/pick positions that are at the facility front; "B" SKUs are located in an aisle middle storage positions; and "C" SKUs are located in an aisle rear storage positions. If the warehouse receiving and shipping docks are located on opposite sides of a facility, fast-moving SKUs are located according to an unload and load ratio. Unload and Load Ratio An unload and load ratio compares the number of trips an unload/storage employee and storage/ load employee require to handle a vendor SKU truck. When an employee's unload/storage trip number equals an employee's storage/load trip number, SKUs are allocated to positions near ship ping docks or any position in an aisle. When an employee's unload/storage trip number is greater that an employee's storage/loading trip number, SKUs are allocated to positions near the receiving dock. This feature reduces employees' total travel distance. Round-Robin A round-robin allocation attempts to spread a SKU quantity evenly over all warehouse storage aisles. With a round-robin, each AS/RS crane or forklift truck handles the same number of fast moving SKUs. A round-robin works best in an AS/RS storage operation, but with an employee conventional forklift truck or operation, it reduces SKU hit concentration and density per aisle. Family Group or Kit A family group or kit allocation is dictated by a company's requirement that SKUs are allocated to a storage position with SKUs that have the same inventory classification or components to a manufacturer's final SKU. Thus, SKUs are assigned by the WMS or warehouse computer to specific storage/pick positions in a zone or aisle. This approach requires that the warehouse storage area be designed to handle SKUs with similar dimensions, weights, or final SKU components in a retail store aisle; normal, refrigerated, or freezer storage conditions; high security, separation of toxic from nontoxic, separation of edible from nonedible, and flammable materials: and that non stackable SKUs are stacked on a special storage or a different pallet size. Pallet or Master Carton Height The design team SKU pallet height options are either a one-pallet or master-carton height that has all storage positions set at the same height; or two-pallet or master-carton heights that has both short and tall storage positions. A pallet or master-carton height design is based on the pallet or master-carton height as it enters the warehouse storage area. A two-pallet or master-carton height design is designed to handle short pallets or master cartons that result from a purchase order quantity that has less than full pallets or master cartons returned from a warehouse. In an AS/RS facility, having short pallets or master cartons openings on lower levels improves structural strength. After storage rack elevations are installed in the warehouse storage area with fire-sprinklers, it is difficult to change the elevation of a pallet or master-carton storage position. This is especially true in an AS/RS crane operation. During an order pick transaction, half-high pallet or master-carton short positions are created; at maximum storage position utilization, a half pallet or master-carton short position number provides maximum storage space utilization. This means that all high-pal let or master-carton short positions have tall pallets or master cartons and not half-high pallets or master cartons. A tall pallet/master carton has greatest number of SKU per pallet with the allowable maxi mum master-carton layers (i.e., that will not crush bottom-layer cartons). A short pallet has fewest number of SKU on a pallet/master cartons per position. When compared to a short-pallet/master carton position, the tall-pallet/master-carton option means fewer transactions or trips; the maxi mum number of SKU on a forklift truck; fewer dock positions; fewer handlings; reduced potential for SKU, equipment, or building damage; and maximum position flexibility. It also increases the need to secure SKUs on a pallet. A two-position design requires the WMS program to flag a SKU for allocation to a specific position. Temperature Sensitive In a warehouse that does not have a temperature-controlled storage area, temperature-sensitive SKUs are allocated by the WMS program to lower storage levels. In a conventional storage design with tall racks, the highest storage positions are the warmest and the floor level positions are cooler. Security In a warehouse with tall-rack storage design and high-value SKUs, most restrictive storage positions are at the top level of the racks. To easily and quickly access rack positions, employees use a forklift truck, which reduces the possibilities of unauthorized access to the positions. If a ware house does not have a high-bay storage section, one can use special cages for which only approved employees have keys, or there can be cameras focused on the entrance. Toxic and Nonedible In a warehouse that handles toxic and nontoxic or edible and nonedible SKUs, toxic or hazardous SKUs require a separate storage area. Many local codes require that toxic SKUs be stored in a storage area with a containment chamber and a holding tank to contain any accidental run-off. If a warehouse handles both edible and nonedible SKUs, many local codes require that nonedible SKUs have a separate storage area and that nonedible SKUs are not stored above edible SKUs. This requires the WMS program to flag a SKU for allocation to a specific position. Flammable In a warehouse that handles flammable SKUs, flammable SKUs require a separate storage area. Many local codes require that flammable SKUs be stored in a warehouse storage area with additional fire-sprinkler protection and barriers to prevent the uncontrolled movement of flammable SKUs. This requires the WMS program to flag a SKU for allocation to a specific position. Golden Highway (Power in One Aisle) The Golden Highway (or power in one aisle) is a warehouse storage/pick design in which high-volume SKUs are located in a single aisle. During pick activity, a Golden Highway design improves a picker SKU hit concentration and density. Power to the Front Power in the front is similar to ABC theory. In this design, high-volume SKUs are placed in aisle front storage positions, with two or three front storage positions left vacant; high-volume SKU initial placement is in the middle or rear storage position. On an off-shift the WMS program directs a forklift truck or AS/RS crane to relocate SKUs from a middle or rear storage position to a vacant aisle front storage position. SKU Inventory Digit Number In a warehouse using SKU inventory digit numbers, SKUs are allocated to storage aisles by the last digit (or last two digits) of the inventory number (e.g., all SKUs that have an inventory last digit of "1" are placed in aisle 1; all SKUs that have an inventory last digit of "2" are placed in aisle 2). If the warehouse receives orders with a large SKU number, SKUs with the same final digit may be allocated to several aisles. Finally, there is a vacant position number between the last two digits, which can be used for SKU expansion and warehouse position flexibility. Overall, use of SKU inventory digit numbers improves employee productivity in returns processing. Storage Design Vehicles A warehouse storage design vehicle has two activities: completing warehouse storage transactions to storage/pick positions and lining up scanners (e.g., facing the scanner [i.e., line-of-sight], RT tag readers) to record SKU and storage position identification. Determining what kind of vehicle should be used will be based on: -- warehouse storage position design -- WMS program -- SKU classification (e.g., pallet, stacking frame, container or pallet cage; master carton; or single items) SKU Storage Put-Away or Withdrawal Transaction Type A SKU put-away or withdrawal storage transaction (i.e., a SKU deposit to a storage position or pick from a storage position) is done by a manually controlled forklift truck or an AS/RS crane. Automated Storage Transaction In a warehouse using an AS/RS crane, the WMS computer directs the crane to the selected storage position. At the storage position, the transaction is completed and the computer received updated information concerning the SKU and its storage position. One option has the WMS computer suggest a position for the SKU and the warehouse computer updates the WMS computer when the transaction is complete. Manual Storage Transaction In a warehouse using manually (or employee) controlled forklift truck, transaction may be manually directed. In this type of transaction, a warehouse employee or lift truck driver determines a vacant storage position. At an employee-selected storage position, the employee completes the physical transfer of the SKU, as well as scanning the SKU identification and storage position, which are sent to the WMS computer. A potential problem with this approach is that the a deposit may not follow the established storage philosophy. Thus, although a manually directed approach functions well in many warehouses, computer-suggested position is preferable in warehouses using a WMS program. Separate Identification Label for Each SKU or Group Each SKU classification has unique storage/pick characteristics with separate storage/pick positions within a warehouse. To facilitate a SKU class movement to the proper storage/pick area- and as a check-a unique component (e.g., digit, numeric, alpha character) in each identification label functions as a SKU classification identifier. Examples of classification identifiers are: Pallet SKU identified by (a) random-number (e.g., 101010PLT, 239499PLT, 728549PLT, 068397PLT), (b) lowest number (e.g., 000001PLT, 000002PLT, 000003PLT, 000004PLT); (c) Julian date with the lowest number (e.g., 0104010 LT, 0204010PLT, 0304010PLT, 0404010PLT); and (d) Julian date with a random number (e.g., 1104010PLT, 0204010PLT, 2304010PLT, 4004010PLT); Master-carton SKU identified by (a) random-number (e.g., 101010MC, 239499 MC, 728549MC, 068397MC); (b) lowest number (e.g., 000001MC, 000002MC, 000003MC, 000004MC); (c) Julian date with the lowest number (e.g., 0104010MC, 0204010MC, 0304010MC, 0404010MC); and (d) Julian date with a random number (e.g., 1104010MC, 0204010MC, 2304010MC, 4004010MC); GOH-SKU identified by (a) random-number identification (e.g., 101010GOH, 239499GOH, 728549GOH, 068397GOH); (b) lowest number (e.g., 000001GOH, 000002GOH, 000003GOH, 000004GOH); (c) Julian date with the lowest number (e.g., 0104010GOH, 0204010GOH, 0304010GOH, 0404010GOH); and (d) Julian date with a random number (e.g., 1104010GOH, 0204010GOH, 2304010GOH, 4004010GOH); Small-item SKU (e.g., jewelry) identified by (a) random number (e.g., 101010JW, 239499JW, 728549JW, 068397JW); (b) lowest number (e.g., 000001JW, 000002JW, 000003JW, 000004JW); (b) Julian date with the lowest number (e.g., 0104010JW, 0204010JW, 0304010JW, 0404010JW); and (c) Julian date with a random number (e.g., 1104010JW, 0204010JW, 2304010JW, 4004010JW); Cold-temperature SKU identified by (a) random number (e.g., 101010CT, 239499CT, 728549CT, 068397CT); (b) lowest number (e.g., 000001CT, 000002CT, 000003CT, 000004CT); (c) Julian date with the lowest number (e.g., 0104010CT, 0204010CT, 0304010CT, 0404010CT); and (d) Julian date with a random number (e.g., 1104010CT, 0204010CT, 2304010CT, 4004010CT); Hot-temperature SKU identified by (a) random number (e.g., 101010HT, 239499HT, 728549HT, 068397HT); (b) lowest number (e.g., 000001HT, 000002HT, 000003HT, 000004HT); (c) Julian date with the lowest number (e.g., 0104010HT, 0204010HT, 0304010HT, 0404010HT); and (d) Julian date with a random number (e.g., 1104010HT, 0204010HT, 2304010HT, 4004010HT). WMS SKU Identification Sequenced in the WMS Program Files After a receiving clerk attaches an identification to a SKU, the clerk scans the identification and enters the associated quantities into the WMS computer files. The WMS computer associates a SKU and quantities with a WMS identifier and tracks the identifier and SKU quantities as they flow through the warehouse. This becomes particularly important during an employee-directed identification withdrawal from a storage position. SKU withdrawals may be completed using the following options: -- oldest identification label or first WMS label scanned -- sequenced by lowest identification number -- by Julian date and lowest WMS label number Picked by Identification or Total SKUs In a single-item or master-carton warehouse (with a floor stack storage design and a WMS pro gram) that uses a conventional forklift truck, as the pallet/carton identification is scanned, an employee enters the associated SKU quantity on a hand-held scanner. The WMS program associates the SKU quantity with the SKU identification. As the identification is scanned and transferred to a storage/pick position and scan transactions are sent to the WMS computer, the WMS program associates the identification with the SKU located in a storage/pick position. As ordered SKUs are transferred from the host computer to the WMS computer, the WMS program allocates the order quantity to an assigned SKU. When the order quantity equals a SKU quantity, the WMS program allocates a SKU quantity to an order pick. The allocation process is completed for each order quantity that equals a full or partial SKU. In a dynamic warehouse, the WMS computer allocated order quantity could equal one full pallet, one full master carton, and one SKU. To ensure accurate SKU counts or inventory, a warehouse has a less than master carton or individual SKU section for less than a full master-carton or individual SKU quantity pick transaction. SKU Identification Options
A WMS program requires that each SKU have an identification or symbology that discreetly identifies one SKU from another SKU (see FIG. 11). The options are: 1. The "one for each" approach, in which each pallet/master carton receives a discreet identification, and is associated with a specific SKU quantity. As the WMS program completes the order SKU allocation process, the program allocates an order for each SKU (pallet/master carton) identification quantity. For each pallet/master-carton SKU quantity, a WMS program prints or creates a warehouse storage/pick WMS move transaction for each SKU quantity. During warehouse forklift truck withdrawal, at a warehouse storage position a forklift truck driver matches a storage position and SKU identification to a warehouse storage position identification and SKU identification. Using this approach will create better forklift driver productivity because employees spend only a minimal amount of time counting master cartons. 2. The "one for all" approach, in which an entire pallet or group of master-cartons has a single identification associated with a SKU. During the withdrawal process for orders, a fork lift driver will need to calculate the pallet/master-carton piece quantity and the actual pallet/master-carton number to match the transaction quantity. This approach has low fork lift driver productivity, more potential errors, and limited position flexibility. Next>> Prev. | Next | Table of Contents |
