KanbanKanban (?), also spelled kamban, pronounced /knbn/, and literally meaning "signboard" or "billboard", is a concept related to lean and just-in-time (JIT) production. According to Taiichi Ohno, the man credited with developing Just-in-time, kanban is one means through which JIT is achieved. Kanban is not an inventory control system. Rather, it is a scheduling system that tells you what to produce, when to produce it, and how much to produce. The need to maintain a high rate of improvements led Toyota to devise the kanban system. Kanban became an effective tool to support the running of the production system as a whole. In addition, it proved to be an excellent way for promoting improvements because reducing the number of kanban in circulation highlighted problem areas.[4]

OriginsIn the late 1940s, Toyota began studying supermarkets with a view to applying store and shelfstocking techniques to the factory floor, based on the idea that in a supermarket, customers get what they need at the needed time, and in the needed amount. Furthermore, the supermarket only stocks what it believes it will sell, and customers only take what they need because future supply is assured. This led Toyota to view a process as being a customer of preceding processes, and the preceding processes as a kind of store. The customer process goes to this store to get needed components, and the store restocks. Originally, as in supermarkets, signboards were used to guide "shopper" processes to specific restocking locations. "Kanban" uses the rate of demand to control the rate of production, passing demand from the end customer up through the chain of customer-store processes. In 1953, Toyota applied this logic in their main plant machine shop.

OperationAn important determinant of the success of production scheduling based on "pushing" the demand is the quality of the demand forecast that can receive such "push." Kanban, by contrast, is part of an approach of receiving the "pull" from the demand. Therefore, the supply or production is determined according to the actual demand of the customers. In contexts where supply time is lengthy and demand is difficult to forecast, the best one can do is to respond quickly to observed demand. This is exactly what a kanban system can help with: It is used as a demand signal that immediately propagates through the supply chain. This can be used to ensure that intermediate stocks held in the supply chain are better managed, usually smaller. Where the supply response cannot be quick enough to meet actual demand fluctuations, causing significant lost sales, then stock building may be deemed as appropriate which can be achieved by issuing more kanban. Taiichi Ohno states that to be effective kanban must follow strict rules of use (Toyota, for example, has six simple rules, below) and that close monitoring of these rules is a never-ending task to ensure that the kanban does what is required. 1

Kanban cardsKanban cards are a key component of Kanban that utilizes cards to signal the need to move materials within a manufacturing or production facility or move materials from an outside supplier to the production facility. The Kanban card is, in effect, a message that signals depletion of product, parts or inventory that when received will trigger the replenishment of that product, part or inventory. Consumption drives demand for more. Demand for more is signaled by Kanban card. Kanban cards thus, in effect, help to create a demand-driven system. It is widely espoused by proponents of Lean production and manufacturing that demand-driven systems lead to faster turnarounds in production and lower inventory levels, helping companies implementing such systems to be more competitive. Kanban cards, in keeping with the principles of Kanban, should simply convey the need for more materials. A red card lying in an empty parts cart would easily convey to whomever it would concern that more parts are needed. In the last few years, Electronic Kanban systems, which send Kanban signals electronically, have become more widespread. While this is leading to a reduction in the use of Kanban cards in aggregate, it is common in modern Lean production facilities to still find widespread usage of Kanban cards.

Toyota's six rules

Do not send defective products to the subsequent process The subsequent process comes to withdraw only what is needed Produce only the exact quantity withdrawn by the subsequent process Level the production Kanban is a means to fine tuning Stabilize and rationalize the process

Three-bin systemA simple example of the kanban system implementation might be a "three-bin system" for the supplied parts (where there is no in-house manufacturing) one bin on the factory floor (demand point), one bin in the factory store, and one bin at the suppliers' store. The bins usually have a removable card that contains the product details and other relevant information the kanban card. When the bin on the factory floor becomes empty, i.e., there is demand for parts, the empty bin and kanban cards are returned to the factory store. The factory store then replaces the bin on the factory floor with a full bin, which also contains a kanban card. The factory store then contacts the suppliers store and returns the now-empty bin with its kanban card. The supplier's inbound product bin with its kanban card is then delivered into the factory store completing the final step to the system. Thus the process will never run out of product and could be described as a loop, providing 2

the exact amount required, with only one spare so there will never be an oversupply. This 'spare' bin allows for the uncertainty in supply, use and transport that are inherent in the system. The secret to a good kanban system is to calculate how many kanban cards are required for each product. Most factories using kanban use the coloured board system (Heijunka Box). This consists of a board created especially for holding the kanban cards.

Electronic kanban systemsMany manufacturers have implemented electronic kanban systems. Electronic kanban systems, or EKanban systems, help to eliminate common problems such as manual entry errors and lost cards. EKanban systems can be integrated into enterprise resource planning (ERP) systems. Integrating EKanban systems into ERP systems allows for real-time demand signaling across the supply chain and improved visibility. Data pulled from E-Kanban systems can be used to optimize inventory levels by better tracking supplier lead and replenishment times.

Material requirements planning (MRP System)

Material requirements planning (MRP) is a production planning and inventory control system used to manage manufacturing processes. Most MRP systems are software-based, while it is possible to conduct MRP by hand as well. An MRP system is intended to simultaneously meet three objectives:

Ensure materials are available for production and products are available for delivery to customers. Maintain the lowest possible level of inventory. Plan manufacturing activities, delivery schedules and purchasing activities.

The scope of MRP in manufacturingThe basic function of MRP system includes inventory control, bill of material processing and elementary scheduling. MRP helps organizations to maintain low inventory levels. It is used to plan manufacturing, purchasing and delivering activities. "Manufacturing organizations, whatever their products, face the same daily practical problem - that customers want products to be available in a shorter time than it takes to make them. This means that some level of planning is required." Companies need to control the types and quantities of materials they purchase, plan which products are to be produced and in what quantities and ensure that they are able to meet current and future customer demand, all at the lowest possible cost. Making a bad decision in any of these areas will make the company lose money. A few examples are given below:

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If a company purchases insufficient quantities of an item used in manufacturing (or the wrong item) it may be unable to meet contract obligations to supply products on time. If a company purchases excessive quantities of an item, money is wasted - the excess quantity ties up cash while it remains as stock and may never even be used at all. Beginning production of an order at the wrong time can cause customer deadlines to be missed.

MRP is a tool to deal with these problems. It provides answers for several questions:

What items are required? How many are required? When are they required?

MRP can be applied both to items that are purchased from outside suppliers and to sub-assemblies, produced internally, that are components of more complex items. The data that must be considered include:

The end item (or items) being created. This is sometimes called Independent Demand, or Level "0" on BOM (Bill of materials). How much is required at a time. When the quantities are required to meet demand. Shelf life of stored materials. Inventory status records. Records of net materials available for use already in stock (on hand) and materials on order from suppliers. Bills of materials. Details of the materials, components and sub-assemblies required to make each product. Planning Data. This includes all the restraints and directions to produce the end items. This includes such items as: Routings, Labor and Machine Standards, Quality and Testing Standards, Pull/Work Cell and Push commands, Lot sizing techniques (i.e. Fixed Lot Size, LotFor-Lot, Economic Order Quantity), Scrap Percentages, and other inputs.

OutputsThere are two outputs and a variety of messages/reports:

Output 1 is the "Recommended Production Schedule" which lays out a detailed schedule of the required minimum start and completion dates, with quantities, for each step of the Routing and Bill Of Material required to satisfy the demand from the Master Production Schedule (MPS).

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Output 2 is the "Recommended Purchasing Schedule". This lays out both the dates that the purchased items should be received into the facility AND the dates that the Purchase orders, or Blanket Order Release should occur to match the production schedules.

Messages and Reports:

Purchase orders. An order to a supplier to provide materials. Reschedule notices. These recommend cancelling, increasing, delaying or speeding up existing orders.

Distribution resource planning (DRP System)

Distribution resource planning (DRP) is a method used in business administration for planning orders within a supply chain. DRP enables the user to set certain inventory control parameters (like a safety stock) and calculate the time-phased inventory requirements. This process is also commonly referred to as distribution requirements planning. DRP uses several variables:

the on-hand inventory at the end of a period. the backordered demand at the end of a period. the required quantity of product needed at the beginning of a period. the constrained quantity of product available at the beginning of a period. the recommended order quantity at the beginning of a period.

DRP needs the following information:

the demand in a future period. the scheduled receipts at the beginning of a period. the safety stock requirement for a period. the on-hand inventory at the beginning of a period.

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WarehouseA warehouse (in India, godown from Malay godong[1]) is a commercial building for storage of goods. Warehouses are used by manufacturers, importers, exporters, wholesalers, transport businesses, customs, etc. They are usually large plain buildings in industrial areas of cities and towns. They usually have loading docks to load and unload goods from trucks. Sometimes warehouses are designed for the loading and unloading of goods directly from railways, airports, or seaports. They often have cranes and forklifts for moving goods, which are usually placed on ISO standard pallets loaded into pallet racks.

Nature of goods storedStored goods can include any raw materials, packing materials, spareparts, components, or finished goods associated with agriculture, manufacturing, or commerce.

Types of warehouse storage systemsSome of the most common warehouse storage systems are:

Pallet rack including selective, drive-in, drive-thru, double-deep, pushback, and gravity flow Mezzanine including structural, roll formed, rack s Vertical Lift Modules Horizontal Carousels Vertical Carousels

Processes of itMajor warehousing processes include:

Receiving Inspection/ Acceptance Proper Storage Order preparation / picking Dispatching/ Delivery Inventory management (Checking as per System vs. Actual stock)o

It can be done daily, weekly, monthly or quarterly.

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Warehouses frequently provide services, such as:

Co-packing Kitting Repair

A piece pick, also known as broken case pick, split-case pick, each pick, over-pack or pick/pack, is a type of order selection process where product is picked and handled in individual units and placed in an outer carton, tote or other container before shipping. Catalog companies and internet retailers are examples of predominantly piece-pick operations. Their customers rarely order in pallet or case quantities; instead, they typically order just one or two pieces of one or two items. Material direction and tracking in a warehouse can be coordinated by a Warehouse Management System (WMS), a database driven computer program. Logistics personnel use the WMS to improve warehouse efficiency by directing putaways and to maintain accurate inventory by recording warehouse transactions.

Automation and optimizationSome warehouses are completely automated, and require only operators to work and handle all the task. Pallets and product move on a system of automated conveyors, cranes and automated storage and retrieval systems coordinated by programmable logic controllers and computers running logistics automation software. These systems are often installed in refrigerated warehouses where temperatures are kept very cold to keep product from spoiling, especially in electronic warehouse where they require specific temperature to avoid damaging the parts and also where land is expensive, as automated storage systems can use vertical space efficiently. These high-bay storage areas are often more than 10 meters (33 feet) high, with some over 20 meters (65 feet) high. Automated storage systems can be built up to 40m high. For a warehouse to function efficiently, the facility must be properly slotted. Slotting addresses which storage medium a product is picked from (pallet rack or carton flow), and how they are picked (pick-to-light, pick-to-voice, or pick-to-paper). With a proper slotting plan, a warehouse can improve its inventory rotation requirementssuch as first in, first out (FIFO) and last in, first out (LIFO) control labor costs and increase productivity.[2]

Modern trendsTraditional warehousing has declined since the last decades of the 20th century, with the gradual introduction of Just In Time (JIT) techniques. The JIT system promotes product delivery directly from suppliers to consumer without the use of warehouses. However, with the gradual implementation of offshore outsourcing and offshoring in about the same time period, the distance between the manufacturer and the retailer (or the parts manufacturer and the industrial plant) grew considerably in many domains, necessitating at least one warehouse per country or per region in any typical supply chain for a given range of products.

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Recent retailing trends have led to the development of warehouse-style retail stores. These highceiling buildings display retail goods on tall, heavy duty industrial racks rather than conventional retail shelving. Typically, items ready for sale are on the bottom of the racks, and crated or palletized inventory is in the upper rack. Essentially, the same building serves as both warehouse and retail store. Another trend relates to Vendor Managed Inventory (VMI). This gives the vendor the control to maintain the level of stock in the store. This method has its own issue that the vendor gains access to the warehouse. Large exporters/manufacturers use warehouses as distribution points for developing retail outlets in a particular region or country. This concept reduces end cost to the consumer and enhances the production sale ratio.

Automated storage and retrieval system

An automated storage and retrieval system (ASRS or AS/RS) consists of a variety of computercontrolled methods for automatically placing and retrieving loads from specific storage locations.Automated Storage and Retrieval Systems (AS/RS) are typically used in applications where: there is a very high volume of loads being moved into and out of storage; storage density is important because of space constraints; no value adding content is present in this process; accuracy is critical because of potential expensive damages to the load.

OverviewAS/RS Systems are devices designed for automated storage and retrieval of parts and items in manufacturing, distribution, retail, wholesale and institutions. They focus on bringing "goods to the man" rather than manual walking and searching. Space savings, increased productivity/reduced labor, increased accuracy and reduced inventory levels are some of the primary benefits. Ideal for lean manufacturing, sustainability, six sigma, Kahnban, JIT and other value added methodologies and processes. The traditional vending machine is the most common and familiar AS/RS system but because the application is to do with retail sales, the logistic concept of a vending machine is missed. Punch in the correct buttons and the item you want becomes available. The trend towards just in time production often requires sub pallet level availability of production inputs, and AS/RS is a much faster way of organizing the storage of smaller items next to production lines. Traditional high bay warehouses are designed with pallet storage in mind, and if goods are being delivered in sub pallet quantities, high bay warehouses are problematic. Material Handling Institute of America (MHIA), the non-profit trade association for the material handling world, and it's members have broken AS/RS into two primary segments. Fixed Aisle and Carousels/Vertical Lift Modules (VLMs). Both sets of technologies provide automated storage and 8

retrieval for parts and items, but use different technologies. Each technology has its unique set of benefits and disadvantages (like everything in the world). Fixed Aisle systems are characteristically larger systems where as Carousels & Vertical Lift Modules are used individually or grouped, but in small to medium sized applications. Fixed Aisle AS/RS is categorized into three main types: single masted, double masted, and manaboard. Most are supported on a track and ceiling guided at the top by guide rails or channels to ensure accurate vertical alignment, although some are suspended from the ceiling. The 'shuttles' that make up the system travel between fixed storage shelves to deposit or retrieve a requested load (ranging from a single book in a library system to a several ton pallet of goods in a warehouse system). As well as moving along the ground, the shuttles are able to telescope up to the necessary height to reach the load, and can store or retrieve loads that are several positions deep in the shelving. A semi-automated system can be achieved by utilizing only specialized shuttles within an existing rack system. To provide a method for accomplishing throughput to and from the AS/RS and the supporting transportation system, stations are provided to precisely position inbound and outbound loads for pickup and delivery by the crane. In addition, there are five types of AS/RS devices called Unit-load AS/RS, Mini-load AS/RS, Vertical Lift Modules (VLMs), Horizontal Carousels and Vertical Carousels. These systems are used either as stand alone units or in integrated workstations called pods. These units usually are integrated with various types of pick to light systems and use either a microprocessor controller for basic usage or inventory management software. These systems are ideal for increasing space utilization up to 85%, productivity levels by 2/3, accuracy to 99.9%+ levels and throughput up to 750 lines per hour/per operator.

Man-aboard AS/RSA man-aboard AS/RS offers significant floorspace savings. This is due to the fact that the storage system heights are no longer limited by the reach height of the order picker. Shelves or storage cabinets can be stacked as high as floor loading, weight capacity, throughput requirements, and/or ceiling heights will permit. Man-aboard automated storage and retrieval systems are far and away the most expensive picker-to-stock equipment alternative. Aisle-captive storage/retrieval machines reaching heights up to 40 feet cost around $125,000. Hence, there must be enough storage density and/or productivity improvement over cart and tote picking to justify the investment. Also, because vertical travel is slow compared to horizontal travel, typical picking rates in man-aboard operations range between 40 and 250 lines per person-hour. The range is large because there is a wide variety of operating schemes for man-aboard systems. Man-aboard systems are typically appropriate for slow-moving items where space is fairly expensive.

Vertical Lift ModuleThe VLM is a computer controlled automated vertical lift module, storage and retrieval system. Functionally, stock within the VLM remains stationary on front and rear tray locations. On request a movable extractor unit travels vertically between the two columns of trays and pulls the requested

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tray from its location and brings it to an access point. The operator then picks or replenishes stock and the tray is returned to its home. VLM system offers variable tray sizes and loads, which could be applied in different industries, logistic, as well as office settings. The VLM systems could be customized to fully utilize the height of the facility, even through multiple floors. With the capability of multiple access openings on different floors, the VLM system is able to provide an innovative storage and retrieval solution. The rapid movement of the extractor as well as the integrated inventory management software can dramatically increase the efficiency of the picking process. Unlike large AS/RS systems, which require a complete overhaul of the warehouse or production line, the Vertical Lift Module are modularized, which can be easily integrated into the existing system, or to be rolled out in gradually over different phases. This is the first model of the same. Most common applications include: MRO, order picking, consolidation, kitting, parts handling, buffering, inventory storage, WIP, buffer storage, and many more. The labor (up to 2/3) and space saving benefits (up to 85%) are primary needs. Most VLMs offer dynamic space storage which measures the tray every time it's returned to the unit to optimize space, tilt tray delivery for increased ergonomic accessibility, and laser pointers which indicate the exact item to be picked on each tray.

Horizontal CarouselsA horizontal carousel is a series of bins which rotate on an oval track. Every bin has shelves which are adjustable to .75" and can be configured for a myriad of standard and special applications. An operator simply inputs a bin number, part number or cell location and the carousel will rotate via the shortest path. Multiple horizontal carousels integrated with pick to light technology and inventory management software (a pod of carousels) are used for order fulfillment. A wave of orders are sent to the pod. A group of orders are selected to create a batch. The operator simply follows the lights and pick round robin from the carousels and place items in a batch station behind them. Each carousel pre-positions and rotates when picked. By applying the "product to picker" principle, operators do not have to move from their position to prepare the order. When the batch is complete, a new batch is inducted and the process repeated until the wave is complete. Horizontal carousels can save up to 75% of floorspace, increase productivity by 2/3, accuracy levels to 99.9%+ levels and throughput up to 750 lines per hour/operator. Horizontal carousel systems generally outperform robotic systems for a fraction of the cost. Horizontal carousels are the most cost effective AS/RS system available. On a simplistic level, horizontal carousels are also often used as "rotating shelving." 'With simple "fetch" command items are brought to the operator and otherwise wasted space is eliminated.

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