The KIVA system is one of the latest innovation in warehousing.
Sunday, January 13, 2008
The Latest Trend - Kiva Systems
The KIVA system is one of the latest innovation in warehousing.
Facilitator's Question
There are a few factors that warehouses have to decide before making the decision. They are, size of the product, value of product, product line and capital availability
Size of the product - This is the main factor to consider when deciding between the two systems. Carousel systems are only suitable to store small items such as drugs whereas live storage are only suitable for pallets or items with a flat surface.
Value of product - The value of product also affects the decision. A product of high value should be placed in the carousel system as it provides much better security as compared to live storage. This is because carousel system stores its goods in a closed container whereas live storage simply stores it on the rack, which makes it easily accessible to potential thieves. Carousel systems are also able to keep track of who and what is taken out from storage whereas live storage is not able to.
Product line - Product lines should be considered as each system handles different product lines differently. Live storage requires the inventory stored on the same row be of the same product line, only then FIFO can be achieved. It is a little bit of fixed location storage. Whereas carousel systems allows different product lines to stored in it. The order picker only need to input what he wants to retrieve and it will be automatically brought to the picker.
Captial availability - This is the limiting factor. The capital limits what a warehouse can install. A carousel system definitely has a higher initial setup cost as it is high tech as compared to live storage. However it ensures more accurate and easier picking as compared to the latter. Less workers are also need to tend to the security of the goods. It has good space efficiency too as compared to live storage.
Saturday, January 12, 2008
Lifting
Today we are only focusing on gantry cranes and scissor lifts.
Gantry Cranes
Gantry cranes travels on floor-mounted rails. It is built to handle large and heavy goods. It can carry up to 200,000kg. Usually gantry cranes are installed at shipyards and steel mills where heavy lifting of ship components are required.
Gantry cranes are cheaper than its alternative which is the bridge crane. The table below shows the cost comparison between the two alternatives.
Gantry crane may have a higher initial setup cost but gantry crane allows you to save up to $17,985 as compared to bridge crane in total cost.
It has a large work area and it allows easy movement of the goods.
However, despite the lower cost, gantry cranes takes up a large space as it is dependent on the rails that are mounted on the floors.
Scissor Lifts
It is used to lift things from a platform to another of another level. It can only be raised vertically. It is operated by hydraulic actuated scissor mechanism under the table. It carry up to around 200,000kg. Scissor lifts can lift up to a height of 12-13m. It is cheap.
It is usually used in the loading and unloading stages of the warehouse operations.
Conveyors
It is high in equipment cost but it is efficient in moving goods around the warehouse. It is useful when other handling equipments could not be used.
There are many different types of conveyors. They are automated guided vehicle, gravity roller conveyors, chutes, skate wheel conveyors, accumulation, flat belt conveyors, slat conveyors gravity conveyor systems, powered conveyors, chain conveyors, tilt try and tilt slat conveyors, overhead chain conveyors. power and free conveyors and under-floor conveyors. Today we are only focusing on automated guided vehicles and gravity roller conveyors.
Gravity Roller Conveyors
It is one of the most popular type of conveyors. It is low in power usage and as its name suggest, it uses gravity. The rollers are spring-loaded so it can be easily removed. Goods must be flat surfaced and it must be smooth and firm.
It it does not, the good will tumble out.
Automated guided vehicles
It is basically vehicles that are driverless. It usually travels on a guided path either by under-floor wiring or by laser-guided or by optically marked paths.
a lightweight production AGV
A laser-guided forklift
AGVs have the ability to make path decisions. There are a few types of decisions to be made. They are the frequency that are transmitted to them by the underground wires, pre-programmed paths and by the magnetic strips that are embedded into the floor, these strips an control the speed of the vehicle.
Picking Equipments
Lift Trucks
Counterbalanced Fork Lift Trucks (CBFLT)
CBFLT have relatively fast. It can carry a weight of 1,000kg to 45,000kg. It is also easy to operate. Smaller models may have 3 wheels instead of 4 so that it is easier to maneuver. There are 2 kinds of CBFLT. One is the sit-down and the other is the stand-up truck.
It can go up to the height of 5m.
It is usually used in the storage and picking stage of the warehouse operation.
Reach Trucks
Reach trucks are driven electrically and it does not have any counterbalance because it does not have a long length. It can carry a weight of 1,000kg to 3,500kg, which is a big difference as compared to CBFLT.
It can go up to a height of 8m
There are 2 kinds of reach trucks. They are double deep and four directional reach trucks.
Double Deep Reach Trucks
It is a type of reach truck whereby it has a longer fork to access double deep racks.
Stacker Trucks
It is a lightweight truck which can carry only up to 2,000kg of goods.
Side loaders
It has a mast which is perpendicular to the direction of the travel. It can handle loafs that are 6-7m long.
One example of usage of side loader is the loading of rods onto cantilever racks.
Free path high rack stackers
It travels on rails in very narrow aisles. The truck can access stock from either side of an aisle. The width of the aisles need not be too wide, as long as it is wider than the goods. Some of them are operated from the ground.
It can go up to the height of 12m.
Stacker crane
It travels on rails that are mounted on the ground and on the ceiling. It has a mast which is responsible for lifting and lowering the carriage to the height required and load into and out of the racking on either side of the crane aisle. It is computer driven, however it can also be manually driven.
It can go up to a height of 30-35m
Non-Lift trucks
Non-lift trucks are usually used to transport goods from one place to another without lifting them from a certain height. There are 2 examples of non-lift trucks. They are trolley, pallet-truck.
Trolley
The platform hand truck is a very common handling equipment. It is suitable to carry a variety of goods. The maximum load for it can be up to 300kg.
It is cheap but it usually requires manual labour.
It is used in almost every stage of the warehouse operations.
Pallet-Trucks
The pallet truck is commonly used to transport pallets around the warehouse. It can be powered or non-powered. The above one is non-powered and it requires manual labour. The handle can be tilted to allow the operator to walk easier while operating it. It does not allow stacking of pallets.
The price of it can vary but the non-powered ones are usually cheaper but it requires manual labour.
Racks
Mechanized system are storage systems that are entirely automated. There are two types of mechanized systems. They are vertical and horizontal. In vertical systems, the carousels can be built to make use of available building height. They are driven electronically. The stock is automatically brought to the operator’s location. This reduces operator movements and give good order packing rate. Stocks are easily accessed. It uses random location storage, thus storage space is fully utilized. Goods are also secured as it is in a protected storage.
The setup can be expensive as it is of high technology and automated. It does not need any vehicle to access the goods.
One example would be the Vertical carousel system
It is used mainly in the picking stage of the warehouse operations
Live Storage
Live storage is a system that supports FIFO. Basically goods are loaded from one end of the rack and unloaded from the opposite end of the rack. This rack is suitable for high throughtput items. Goods can be carton boxes or any unit load with a flat surface as it uses roller conveyor belt.
This setup is very expensive as compared to the other 2 racking system and it can be accessed by a fork truck.
It is used mainly in the picking stage of the warehouse operations.
Our Focus
This topic is vast topic which covers a wide range of activities in a warehouse. It can be interlink with Receving & shipping dock operations, storage systems and many more.
In the following weeks we will post entries about the different kind of equipments that are used in a warehouse. In each entry, we will detail at which stage is it used.
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