Thursday, January 10, 2008

Facilitator's Question:

Under what circumstances the carton flow rack is a preferred choice as compared to other carton storage system?

Since movement comprises a major part of the carton pickers’ effort, it shows the importance in minimizing factors that contribute to order picker’s job. For instance, many pharmaceutical supply houses use flow racks because the front picking face permits a large number of items to be available to the order picker, thus decreases the walking distances and time significantly.

The carton flow racks is said to be most suitable for products when the frequency of issuing the items is relatively high. The several advantages over the other carton storage system are namely:

  • Followed by reducing the distances travelled and time incurred, carton flow racks eliminate the aisles required for standard carton storage system
  • They can be restocked at the same time while picking of orders is performed on the front of the picking face as replenishment could be done from the back
  • First- In- First- Out (FIFO) control of inventory is assured
  • Employees do not have to be psychologically and physically prepared for the working heights as the flow racks are easily reachable to the pickers. Unlike the carton storage system where high stacking of products are concerned, material handling equipment is incorporated to rise pickers to the respective locations in the racks
  • The number of line items for the front, picking can be dramatically higher than for carton storage system
  • Makes full use of floor space with restocking and picking done separately. This will cover up the disadvantage of the lack in height
  • Minimum supervision needed on the workers
  • Minimize human errors
  • Level of inventory easily visible to workers
  • Easy installations with add-ons to allow for customization
  • Racks built in workstations
  • Pick conveyor - mounted onto the racks can act as a pick or take-away
  • Wheels added to increase mobility of racks

However, there maybe restrictions to the carton flow rack compared to the normal carton rackings. For example, the height restriction of the rackings. Carton flow rack may be only able to hold up to a certain height limit thus cartons that are of bigger size may not be able to be fit into the racks. Cartons flow racks may also be suitable for items that are picked in EACH quantity(EA). This is because it could hold a high number of SKUs and may not need to be replenished often.

Overall, carton flow racks would be a good choice as it could hold a high number of different SKUs and could allow maximum utilization of the warehouse. However, there are some restrictions of the racking that are to be considered. Moreover, the types of products, the characteristics of the products and how the products are picked should also be looked into.

The above was posted by the LIM KAI SIANG, LIM RUI XIANG, LIM SIEW KIANG, NG SIYUN HEIDI

Mezzanine Flooring


A mezzanine floor is essentially a raised platform that is supported by steel columns and is totally independent of the host building. It allows you to create additional floorspace from wasted air space above your existing work and storage areas and can be used to create extra office, storage, production, or even retail space. This may double, or even triple, the amount of space available.

Thus this will be able to have more shelvings to put the SKU in place. Basically Mezzanine Flooring maximised the height usage of the warehouse and thus optimizing the cubic area of it. It is a good alternative to store the items with the help of Mezzanine Flooring if the warehouse's height is rather high and by doing this, it will create more space to store other bulky items and this in turns helps to generate more profit and cut down costing in the long run. However, the drawback of this is that the startup cost of the infrastructure is rather high.


Here are some advantages of the Mezzanine Flooring:

  • Cost-efficient increased space
  • Fully demountable, so they can be relocated at a later date
  • Increased potential storage space
  • Avoids relocation costs by making use of available space
  • Flexible design option, can be used for many purposes
  • Excellent fire protection available
  • Lightweight, economic steel structure
  • Bespoke design to meet precise customer requirements
  • Seamless integration within existing environment
  • Fast-track construction, with minimum disruption
  • High quality, powder coated ancillaries in a wide choice of colours

Though Mezzanine Flooring helps to create more space for the SKU, however, in order to optimize the efficiency of it, Barcoding technology and using of "U" flow and "through" flow for the layout arrangement of it is recommended to be implemented in it.

Mezzanine floors can also be constructed within racking or shelving systems to create a double decked storage area.

Source: http://sg.images.search.yahoo.com/

The above was posted by KAI SIANG

Partitioning

Partitioning means something that divides or separates, as a wall dividing one room or cubicle from another and this is essential in the warehouse as there are several categories of products and could not be mixed together due to the nature of it.


There are several types of partitioning for a warehouse:

Broadsword



Broadsword is a heavy duty, economic industrial single skin steel partition which is ideal for secure storage and protective screening in the harshest industrial environments. Its angle frame gives the system flexibility and it can be dismantled and relocated quickly and easily for minimum disruption.

Sabre



Sabre is a medium duty single skin partitioning ideal for use in factory, warehouse and production office areas. In a multi-tiered form, it is effective for dividing up factories or warehouses to provide security, dust proofing and/or heat control. It is easily cut to fit around obstructions that frequently occur at high levels. Other applications include perimeter guarding to automated machinery, robots, conveyors and other manufacturing processes.

Excalibur



Excalibur is a high quality, double skin steel partition which is flush both sides and ideal for creating offices and clean rooms in production areas or warehouses. Panels are of a monobloc construction with two steel skins separated by an inert mineral wool insulating infill.It offers hidden cable management and double glazing that is available with blinds. Excalibur is also offered complete with a full range of proprietary suspended ceilings with tiles that cover the full spectrum of textures and styles. The system is also available in a fire rated version.

Scimitar
Scimitar is a mesh partitioning system which is fast and simple to install, fully relocatable and demountable. Scimitar mesh panels enable stored/protected items to be viewed and is ideal for bonded areas, hazardous goods, and high value goods storage. Scimitar is also suitable for use outdoors and cold room/refrigerated storage and all indoor applications.


Anti-Collapse Mesh Screen




Anti-Collapse Mesh screen system represents a simple preventative measure which has helped avoid many accidents in the handling of pallets. The mesh wire is mounted on sturdy brackets designed to fit racking of almost any design. The product can be adapted to suit a wide variety of situations. The mesh is all welded.

Source: http://sg.images.search.yahoo.com/

The above posted by KAI SIANG

Location Address plays an IMPORTANT Role in Storage Systems

The location address system is a systemic process of identifying, determining and naming all racks/ shelves. Existence of a consistent and unambiguous identification for both retail and medium warehouses can facilitate ease of locating products in picking, replenishment and counting stocks.

In addition, it is important to store the heavy items that have to be lifted by material handling equipment such as pallet truck. To emphasize ergonomics, fast- moving products should be stored between the belt and shoulder height level. Hence workers can pick with minimal stretching and bending.

A combination of alphabets and numeric markings helps to identify individual location address (e.g. A- 018-100) that holds each product. The idea of having a product code assigned to a location (a slot in the racks), that segregate storedc products. During picking, workers' effort may be eliminated when sorting of the different products at a location is no longer necessary. Distributors have to be aware that the numbers of digits/alphabets should cater for future expansion- in order to have a standardized and unique (non- repetitive) identification.

Below are 2 examples for naming the location:


The diagram below shows the 2 sides to an aisle (if any). Besides running the digits in consecutive order, even or odd can be used to name the either side of the racks/ shelves.

Example 1




Example 2




Example 3


The above was posted by HEIDI

Zoning of Storage Area

After classifiying products into fast, moderate and slow moving, storage area is divided into three major zones: A item zone, B item zone and C item zone. In addition, storing products that often appears on the same customer orders near one another can minimize movement in warehouses.

A Item Zone

  • Also known as “golden zone” where it is near the primary aisles, packaging area and entrances and exit
  • Recommended for storing fast moving inventories
  • Wider aisles width to allow more frequent picking by workers at the zone
B Item Zone


  • Cater to moderate-moving inventories
  • Narrower aisles width

C Item Zone

  • Stores slow-moving or non- planned products
  • Usually located away from primary aisles or on the high/low racks or shelves

The positioning of the A, B and C zones at the storage area should be in accordance to the flow of the products. This aims to minimize movement, backtracking and cross-traffic (where flow crosses). The red line below indicates the flow of products.

'U' Flow

'Through' Flow

The above was posted by HEIDI


Gravity Flow Racks

Gravity flow racks are rackings that have rollers and are built at an angle in order for the cartons to roll down to ease the picking. Items are replenished from the rear and picked from the front. This will help increase productivity and it could be used for small items/cartons and even to pallets. Moreover, this could also help ensure first-in-first-out inventory management system is being carried out. This could be built on the ground level or on the mezzanine floorings. This will creates more locations for storage or even picking. Below are some pictures of a gravity flow racks.


The above was posted by SIEW KIANG
Non- Palletized Storage System (Odd Size Storage)

Basically, the types of rackings to be used in the warehouse will depends on the products that the company is storing. Below are the few types of rackings for different types of products.

Cantilever Racks

Cantilever rackings are unlike other conventional rackings, where there are vertical obstructions in the racks that separate the rackings into different sections. For cantilever rackings, it gives you a frontal access to the products and the main advantage is that it allows you to store products of various lengths, size or shapes. For example, steel bars, lumbers, etc are suitables to be stored using the cantilever racks. Below are the picture of a cantilever rack.

Stanchion Racks
Stanchion racks are another choice of rackings that allows you to store bars or tubes. It does not requires any special fittings, thus you could fix it up for storage anytime you want to - instantly. It could be joined to the desired length required and the individual racks could be stacked on top of one another. However, the disadvantage is that it would take up some space when it is not in use. Below is a picture of how a stanchion rack looks like.

Above info are taken from http://www.cantileverracking.biz/.

The above posted by SIEW KIANG


Non- Palletized Storage (Small Item Racks, Carton Racks and Shelving)

Although pallets are commonly used in warehouses, there are products that are not suitable for palletization, because they are too small, too large, too long and etc. Some of these examples include bearings, carpets, drums and etc.

Various storage systems are designed to hold small items. They are namely small item racks, carton (bin) racks, shelving and etc. Below are some pictures of the non- palletized storage system.

Pictures taken from local and overseas bearing company. The logo is blanked out to protect the confidentiality of the company.

Small Item Racks

Shelving is usually made from mild steel in its standard component sizes to the different heights. It is considered inexpensive and gives random access to the products. It has be known that adjustment to the shelf heights is not easy after a certain period of usage. Shelving can be installed at multiple levels. The lighter products are recommended to be placed on the top shelves and heavier at the bottom. Refer to Location Addresses Plays An Important Role in Storage System for more details.
Carton Racks

Small easily handled cartons which store products of manageable weights, are placed in the different "slots" of the racks. Not only does this form of storage has to be in cartons; some uses tote pans and bins. The tote pans can be preferred to cartons as they are made of plastics and are more durable.

The above was posted by HEIDI
Automated Storage Retrieval System

Automated Storage Retrieval System which is also known as ASRS for short is a very powerful system that helps to store and retrieve items automatically. And by automatically, it actually eliminates the amount of hassle required and labour involved to do these activites, in turns this actually reduce human errors, reduces inventory, cost, save time and increase efficiency and productivity rate. This is a system that is being used widely by companies as ASRS helps to save costs in the long run.

When storing the items, the system will show if there is any space for the storing of it. The warehouse specialist will than choose the location and place the items on the conveyor, after scanning the items, it will be stored and recorded to the system.

When retrieving, the warehouse specialist will just have to scan the picklist with the scanner and the system will automatically retrieve out of the system and than remove it from the system.

In order to have a clearer and better understanding of the system, here is a video that i got from youtube to show how the ASRS work

The above was posted by KAI SIANG
Adjustable Pallet Racking (APR)
Can APR be categorized under both Palletized and Non- Palletized Storage System?

The answer is YES

Although Adjustable Pallet Racking (APR) is commonly used for palletized storage, accessories are available for it to store non- palletized products such as drums.

APR can be built to match the lift height of any forklifts. When necessary, the height of the beams can be adjusted to suit the height of the storage materials (e.g. pallets and drums).
One important consideration to incorporate APR was that it is fairly inexpensive; which makes it appealing to most warehouse owners. Also, APR is said to be a flexible and versatile storage system which provides good stock accessibility. Unlike bulk stacking, APR can be suitable for fast and slow moving products which have many product lines.

At any one point of time, the material handling equipment (e.g. forklift truck) is only accessible to the two rows of racking. This reduces the space utilization. Also, if the racking height were to go above 8 metres, flat floor is necessary to reduce the risks of the load colliding into the racks.

Pictures retrieved from http://racking-adjustable.co.uk/
The above was posted by HEIDI
Double Deep Pallet Racking



Source retrieved from http://www.engprod.com/images/doubledeep.jpg


Like any other racking system, it requires an aisle and thus result in poor costly warehouse space utilization.

Advantages

  • Enhance space utilization which ultimately reduce the total warehousing costs incurred
  • Two pallets can be reached by the double deep trucks in the racks
  • With the increase in rack height, products are more prone to damages as more handling is required

Disadvantages

  • The need to have double reach trucks
  • Lost of absolute FIFO
  • Poor visibility for the truck drivers when accessing the rear locations
  • Ergonomics is not enhanced; frequent bending and stretching required by workers who pick products from the deeper racks

The above was posted by HEIDI

Mobile Pallet Racking

Mobile racking is the easiest to configure when talking about utilising the most space available in storage of pallets. The rack being mounted on a mobile chassis is able to move along the guided rails installed in the floor. This method is most ideally used in cold stores where maximum space is required.



Personally I prefer the mobile pallet racking system out of the many that was found. This method is able to fully utilise the space available and store to the maximum capacity. One point that particularly impresses me was that there is 100% access to the pallets on the rack. Unlike other racking systems, there will always be some constraints in retrieving the pallets. Whether it can be retrieve from only one side or a larger space is required to cater for a wider aisle. Although the mobile pallet racking is an ideal method, I also understand that it will be quite costly to install the system.
Source: http://www.storax.org.uk/solutions_mobile.htm

The above was posted by RUI XIANG
Wide Aisle

Wide aisle racking is the most commonly used method for storing palletised loads. The width of the aisle can be separated based on the users’ existing fleet of forklifts. The aisles can be single or double sided depending on the users need.

Narrow Aisle

Similar to the wide aisle racking system, Narrow aisle racking used the same basic components. The differences are that the space between each rack is now packed closer so that space will be utilised fully. Second, pallets can also be stacked higher to maximise on the space available. Lastly, the use of Narrow aisle would require specialised trucks which will be guided in the aisles using wire in the floor or floor mounted guide rail.
Very Narrow Aisle

This method is the most efficient way in terms of space utilisation. This is so as aisle widths are kept to a minimum in order to achieve the efficiency. With the help of the crane, it is able to store pallets to heights up to 30 metres.
The above was posted by RUI XIANG
Drive- Through

This method is used frequently in warehouses or facilities where there are a low number of product lines which also means that there will be a high storage density required by the user. In this method, the first pallet put in will be the last pallet out as there is only one operating aisle. Unless a Drive Through system is used, whereby pallets can be retrieved from either side of block.
The above was posted by RUI XIANG
Block Stacking

In block stacking, loaded pallets are directly stacked onto the floor and built up in stacks, one pallet on top of another without the need for any storage equipment. Warehouse safety has being one of the primary concerns, it is recommended to have a maximum stable height of stacks (e.g. usually not more than six pallets). This aims to prevent incidents where stacked pallets were to topple.

Ideally, any one row of pallets should contain pallets of the same products to avoid double handling and to simplify records of stock locations (where possible). When setting out the simple block stacking, clearances should be allowed for the movement of forklifts. It is recommended to have lines painted on the floor to help maintain the layout disciple.

Free access to retrieval of these pallets is limited only to pallets on top/ front of each row, or at the sides. Thus difficulties may be encountered in practicing First- In- First- Out (FIFO). This is especially the case for pallets which are situated in the ‘middle’ or ‘bottom’ of the blocks.Block stacking is said to be more suitable for stored products which have only few product lines, each with high inventory level to ensure FIFO movement of inventory. Hence it is a good practice to empty a row completely before replenishing any more products into that row.

With no storage equipments required, it provides flexibility for the warheouse to change the layout of blocks (when necessary). Below is a pictures are taken from a local bearing company, to illustrate bulk stacking in a warehouse. The logo has been blanked out to protect the confidentiality of the company.

Advantages
  • Best space utilization; cubic utilization
  • Low storage costs incurred

Disadvantages

  • Increase material handling costs since FIFO is usually practised in warehouses and additional costs will be incurred
  • When storing different products in blocks, more time and effort can be made by the workers to to identify, move and shift the right product

The above was posted by HEIDI

Pallet Racking



Storage of goods in a warehouse normally involves the stacking of pallets, with one pallet on top of another or placing the pallets into some form of racking. The wooden pallet is the most common unit load used in warehouses. It is said to be a convenient- sized unit load for moving products around the warehouse and for the its storage. As products are usually received in pallets, they are usually considered the "standard" or "basic" components in a warehouse. It enables standard storage and incorporation of material handling equipments such as forklifts, irrespective of the nature of products stored in the pallets. Take one of the local bearing company as an example, the picker (referring to the figure below) was picking the boxes of bearings from the pallets in the racks. In this case, the pallets are used as a form of storage in the warehouse. A wide range of equipment is available for effectively and efficient movement of pallets in the warehouses. The logo was blanked out to protect the confidentiality of the company.



There are many storage systems available for palletized for palletized products, ranging from simple block stacking to advanced computer- controlled storage system such as Automated Storage and Retrieval System (ASRS). The various palletized storage systems mentioned later will compromise between the very dense storage of pallets with limited accessibility to each pallet and individual accessibility to every pallet, with the expense of occupying more warehouse space.

The above was posted by HEIDI
The choice of storage system should allow:

  • Effective warehouse space utilization; making good use of building volume by choosing the right storage system, good planning for warehouse layout and minimising aisle widths
  • Accessibiliity to stored products; minimizing distances travelled which ultimately reduce time taken to locate the products
  • Incorporate system to keep track of stock movement and locations
  • Ability to secure the property against damage, fire, theft, and etc
  • Provide an environment where it prevents deterioration, contamination of stock and etc

Factors that influences the choice of storage medium are stated below:

  • Physical characteristics of products being stored in the warehouse (e.g. size, shapes, weight and whether they can be stacked)
  • Capital availability (e.g. costs of racking system, incorporating a computerized system to track the products and etc)
  • Accessibility to products stored
  • Stocks and throughout level
  • Number of line items
  • Value of stored products
  • Characteristics of available storage methods and equipment
  • Hazard factors such as fire, noxious gaeses and etc
  • Deterioration factors that affects the product life

Note:

In FIXED location, any given given location within the warheouse is only catered to store a specified product line. Mainly, the fixed location is at the Order Picking area. The order picker will be very familiar with the storage location, hence, it is faster in picking the items.

On the other hand, RANDOM location is usually adopted at Main Store area where when a designated location is empty, it can be used to hold any other product line. This is ideal for main store area as the bulk pack products are just unloaded. Since the cycle time is critical to clear the unloading bay, random method is faster (and save space) so long as there is an appropriate storage location for the bulk products.

The above was posted by HEIDI

INTRODUCTION

The primary objective of storage in a distribution warehouse is simply to store the Stock- Keeping Unit (SKUs) in a location temporarily; until they are required for customer order. In order to select the appropriate storage system for the warehouse(s), it involves the matching of storage and throughput requirements to the equipment characteristics. This means to compromise between maximising the use of storage space and the need for accessibility to stored products.

Storage Methods

The various storage methods discussed later would eventually look at the palletized and non- palletized (e. g. Small Item Storage and Odd Size Storage) storage system.
The coverage would comprise of the followings:

Palletized Storage System
  • Pallet Racking
  • Block Stacking
  • Drive- Through and Drive- In Racking
  • Wide Aisle Racking, Narrow Aisle Racking, Very Narrow Aisle Racking
  • Mobile Pallet Racking
  • Double Deep Pallet Racking
  • Adjustable Pallet Racking (ARP)
  • Automated Storage and Retrieval System (ASRS)

Non- Palletized Storage System

Small Item Racks

  • Carton Racks
  • Shelvings

Odd Size Storage

  • Cantilever Racks
  • Stanchion Racks

On top of that, Gravity Flow Racks could be used for small items and pallets

ADDITIONAL

  • Zoning of Storage Area
  • Location Address plays an IMPORTANT Role in Storage Systems
  • Partitioning
  • Mezzanine Flooring