What types of Order Picking and Assembly Systems?

Order picking can be defined as the activity by which a small number of goods are extracted from a warehousing system, to satisfy a number of independent customer orders. Picking processes have become an important part of the supply chain process. It is seen as the most labor-intensive and costly activity for almost every warehouse, where the cost of order picking is

much as55% of the total warehouse operating expense. As the order picking process involves significant cost and can affect customer satisfaction levels, there have been increasing numbers of process improvements proposed to help companies with this supply chain issue.

Solutions For Order Picking

A number of supply chain academics such as G.P. Sharp and Edward Frazelle have proposed a number of ways of classifying the order picking system. Four solutions have been identified for order picking.

• Picker to Part
• Part to Picker
• Sorting System
• Pick to Box

Picker To Part

This particular method is very common and found in most warehouse environments. The process involves a storage area, a picking area and a material handing system that is used to refill the picking locations from the storage area, which can be forklift based or more specialized such as gravity flow racks. The storage area will contain the items required to fulfill the customer orders. The picking operator can then pick the items for

each customer order from the items stored in the picking area. As all the items are in a smaller area than the regular warehouse, the picking operator can fulfill the order more efficiently than if they had to pick the items from the general storage area in the warehouse. The gravity flow racks are especially useful for items that are commonly ordered so the picking operator can be in one location and pick items from the trays in front of them. There are a number of technological advances in “picker to part” processes such as “pick to light” or “voice picking”. These systems allow picking operators are informed which item to pick based on a light appearing on the item location or a voice informing the operator on a headset which item to pick.

Part To Picker

The part to picker method employs the same physical locations as the previous method; storage area, picking area and a material handling system that moves the items from the storage area to the picking area. The difference with this method is that the picking area is made up of a series of picking bays. The items are moved from the storage area and delivered to the picking bays. Each bay receives the items for one or more orders. The picking operator collects the items delivered to their bay and the customer order is fulfilled in this manner. This method can be subject to wasted labor as picking operators can find themselves waiting for items to be delivered to their picking location.

Sorting System

The sorting process including the requirement for a picking area, a storage area, replenishment of the picking area and a sorter. This method uses automatic material handling system consisting of multiple conveyors and a number of sorting devices. The items are placed on a conveyor in the storage area and the items are sorted for each particular order. The operator in the picking area collects the items that have been sorted for a customer order and processes that order. The efficiency is gained because the operator does not have to consume time collecting individual items.

Pick To Box

Pick to box is similar to the sorting solution as it uses the same elements; a picking area, a storage area, replenishment of the picking area and a sorter. The picking area is organized so that there are a number of picking zones connected by a conveyor system. The operator fills the box with the items on a customer order and the box moves to the picking zones until the customer order is complete and it is then ready for shipment to the customer. The efficiencies are gained because the operator does not have to consume time collecting individual items, but the cost of the initial set up of this solution could negate any cost benefits that the solution offers.

Choosing an order picking system depends on any number of requirements such as cost, complexity, number of customer orders, size and number of items, etc. Every company has a unique requirement and one order picking solution may suit one business and not another. Determining the requirements will ensure that the most efficient order picking solution is selected.

 

 

 

 

http://en.wikipedia.org/wiki/Order_picking

We can identify the following main types of order picking:

• piece picking or picker to part method: the order picker(s) move(s) to collect the products necessary for one order
• zone picking method: each order picker is assigned to one specific zone and will only realize order picking within this zone
• wave picking method: the order picker(s) move(s) to collect the products necessary for several orders
• sorting systems method: no movement of the order picker(s), the products are brought to him by an automatic system (conveyor system, automatic storage ...).
• pick to box method: no movement of the order picker(s), the picking area is organized so that there are a number of picking stations connected by a conveyor. The order picker fills the box with the products from his station and the box moves to the other picking stations until the customer order is complete.

 

assembly by hand and automated comes to mind... not sure in which context it is to be taken.

I have seen off site warehouses which assembled for a major tool manufacturer their tool sets by hand .. I have seen our crew rework and assemble items for a customer by hand ...

most car manufacturers have automated/robotic assembly lines... I personally have not seen this type of assembly process where a3rd party logistic firm is providing such work

Agree with the answers logged

The methods for order picking vary greatly and the level of difficulty in choosing the best method for your operation will depend on the type of operation you have.  The characteristics of the product being handled, total number of transactions, total number of orders, picks per order, quantity per pick, picks per SKU, total number of SKUs, value-added processing such as private labeling, and whether you are handling piece pick, case pick, or full-pallet loads are all factors that will affect your decision on a method for order picking.  Many times a combination of picking methods is needed to handle diverse product and order characteristics.

Key objectives in designing an order picking operation include increases in productivity, reduction of cycle time, and increases in accuracy.  Often times these objectives may conflict with one another in that a method that focuses on productivity may not provide a short enough cycle time, or a method that focuses on accuracy may sacrifice productivity.

• Productivity.  Productivity in order picking is measured by the pick rate.  Piece pick operations usually measure the pick rate in line items picked per hour while case pick operations may measure cases per hour and line items per hour.  In pallet pick operations the best measure is actual pallets picked per hour.  Since the actual amount of time it takes to physically remove the product from the location tends to be fixed regardless of the picking method used, productivity gains are usually in the form of reducing the travel time.
• Cycle Time.  Cycle time is the amount of time it takes to get an order from order entry to the shipping dock.  In recent years, customer’s expectations of companies to provide same day shipment has put greater emphasis on reducing cycle times from days to hours or minutes.  Immediate release of orders to the warehouse for picking and methods that provide concurrent picking of items within large orders are ways to reduce cycle times.
• Accuracy.    Regardless of the type of operation you are running, accuracy will be a key objective.  Virtually every decision you make in setting up a warehouse will have some impact on accuracy, from the product numbering scheme, to the design of product labels, product packaging, the design of picking documents, location numbering scheme, storage equipment, lighting conditions, and picking method used.  Technologies that aide in picking accuracy include pick-to-light systems, counting scales, and bar code scanners.  Beyond the design aspects of an order picking operation, employee training, accuracy tracking, and accountability are essential to achieving high levels of accuracy.

Piece Picking

Piece-picking methods.  

Piece picking, also known as broken case picking or pick/pack operations, describes systems where individual items are picked.  Piece pick operations usually have a large sku base in the thousands or tens of thousands of items, small quantities per pick, and short cycle times. Mail order catalog companies and repair parts distributors are good examples of piece pick operations.

• Basic order picking.  In the most basic order-picking method, product is stored in fixed locations on static shelving or pallet rack.  An order picker picks one order at a time following a route up and down each aisle until the entire order is picked.  The order picker will usually use some type of picking cart.  The design of the picking flow should be such that the order picker ends up fairly close to the original starting point.  The picking document should have the picks sorted in the same sequence as the picking flow.  Fast moving product should be stored close to the main cross aisle and additional cross aisles put in to allow short cuts.  Larger bulkier items would be stored towards the end of the pick flow.  This basic order picking method can work well in operations with a small total number of orders and a high number of picks per order.  Operations with low picks per order will find the travel time excessive in this type of picking and operations with large numbers of orders will find that the congestion from many pickers working in the same areas slows down the processing.
• Batch picking / Multi-order picking In batch picking, multiple orders are grouped into small batches. An order picker will pick all orders within the batch in one pass using a consolidated pick list.  Usually the picker will use a multi-tiered picking cart maintaining a separate tote or carton on the cart for each order.  Batch sizes usually run from4 to12 orders per batch depending on the average picks per order in that specific operation.  Batch picking systems may use extensive logic programmed to consolidate orders with the same items.  In operations with low picks per order, batch picking can greatly reduce travel time by allowing the picker to make additional picks while in the same area.  Since you are picking multiple orders at the same time, systems and procedures will be required to prevent mixing of orders.  In very busy operations, batch picking is often used in conjunction with zone picking and automated material handling equipment.  In order to get maximum productivity in batch pick operations, orders must be accumulated in the system until there are enough similar picks to create the batches.  This delay in processing may not be acceptable in same day shipping operations.
• Zone picking. Zone picking is the order picking version of the assembly line.   In zone picking, the picking area is broken up into individual pick zones. Order pickers are assigned a specific zone, and only pick items within that zone.  Orders are moved from one zone to the next as the picking from the previous zone is completed (also known as "pick-and-pass").  Usually, conveyor systems are used to move orders from zone to zone.  In zone picking it’s important to balance the number of picks from zone to zone to maintain a consistent flow.  Zones are usually sized to accommodate enough picks for one or two order pickers.  Creating fast pick areas close to the conveyor is essential in achieving high productivity in zone picking.  Zone picking is most effective in large operations with high total numbers of skus, high total numbers of orders, and low to moderate picks per order.  Separate zones also provide for specialization of picking techniques such as having automated material handling systems in one zone and manual handling in the next.
• Wave picking.  A variation on zone picking and batch picking where rather than orders moving from one zone to the next for picking, all zones are picked at the same time and the items are later sorted and consolidated into individual orders/shipments.  Wave picking is the quickest method (shortest cycle time) for picking multi item orders however the sorting and consolidation process can be tricky.  Operations with high total number of SKUs and moderate to high picks per order may benefit from wave picking. Wave picking may be used to isolate orders by specific carriers, routes, or zones.

Basic Order Picking Total Orders:       Low Picks Per Order:  Moderate to High   Batch Picking    Total Orders:        Low to High Picks Per Order:  Low   Zone Picking    Total Orders:       Moderate to High Picks Per Order:  Low to Moderate   Wave Picking    Total Orders:       Low to High Picks Per Order:  Moderate to High  

Piece-picking equipment: 

As with the picking methods, the picking equipment used will also depend on a variety of factors.

• Static shelving.  The most common equipment for storage in piece pick operations, static shelving is designed with depths from12” to24”.  Product is either placed directly on the shelving or in corrugated, plastic, or steel parts bins.  Static shelving is economical and is the best method where there are few picks per SKU or where parts are very small.
• Carton flow rack.  Carton flow rack is similar to static shelving with the exception that rather than shelves, there are small sections of gravity conveyor mounted at a slight angle.  Product is stocked from the rear of the flow rack and picking is done from the face.  Product can be stocked in cartons or small totes or bins. As a carton or tote is emptied, it is removed from the rack and another one will roll into place.  Carton flow rack is most useful where there is a very high number of picks per SKU. 
• Carousels.  Horizontal carousels are a version of the same equipment used by dry cleaners to store and retrieve clothing. They have racks hanging from them that can be configured to accommodate various size storage bins.  Generally an operator will run2 to4 carousels at a time avoiding the need for the operator to wait while one unit is turning.  Picking is usually performed in batches with orders downloaded from the host system to the carousel software.  Horizontal carousels are most common in picking operations with very high number of orders, low to moderate picks per order, and low to moderate picks per SKU.  Horizontal carousels provide very high pick rates as well as high storage density.   Pick-to-light systems are often integrated into carousels. Vertical Carousels are frequently used in laboratories and specialty manufacturing operations and are rarely used in regular order picking operations.
• Automatic storage and retrieval systems (ASRS).  An ASRS is a system of rows of rack, each row having a dedicated retrieval unit that moves vertically and horizontally along the rack, picking and putting away loads.  ASRS systems are available in mini-load types that store and transfer product on some type of tray or in bins, and unit-load types that transfer and store pallet loads or other large unitized loads. In addition to the automation features, ASRS units can provide extremely high storage density with capabilities to work in racking up to100 feet high.  Unfortunately the high costs of ASRS equipment and the length of the retrieval times make it difficult to incorporate into a piece picking operation.
• Automatic picking machines.  Fully automated picking machines (such as A-frames) are still pretty rare and are used only where very high volumes of similar products are picked such as music CDs, or,  where high volume in combination with high accuracy requirements exist such as pharmaceutical fulfillment.
• Pick-to-light.  Pick-to light systems consist of lights and LED displays for each pick location.  The system uses software to light the next pick and display the quantity to pick.  Pick-to-light systems have the advantage of not only increasing accuracy, but also increasing productivity.  Since hardware is required for each pick location, pick-to-light systems are easier to cost justify where very high picks per SKU occur.  Carton flow rack and horizontal carousels are good applications for pick to light.  In batch picking, put-to-light is also incorporated into the cart or rack that holds the cartons or totes that you are picking in to.  The light will designate which order you should be placing the picked items in.
• Bar-code scanners.  Though very useful in increasing accuracy levels, bar-code scanners in a fast-paced piece-pick operation tend to become cumbersome and can significantly reduce your pick rates.  With proper training, tracking, and accountability, you can get very high accuracy rates in order picking without scanners.   I find they are better suited to case pick, pallet load, putaway, and order checking operations.
• Voice-directed picking.  Voice technology has come of age in recent years and is now a very viable solution for piece pick, case pick, or pallet pick operations.
• Automated conveyor and sortation Systems.  Automated conveyor systems and sortation systems will be integral to any large-scale piece pick operation.  The variety of equipment and system designs is enormous.

I agree with Mr. hany       .

I fully agree with the answers been added by EXPERTS . Thanks

The methods for order picking vary greatly and the level of difficulty in choosing the best method for your operation will depend on the type of operation you have.  The characteristics of the product being handled, total number of transactions, total number of orders, picks per order, quantity per pick, picks per SKU, total number of SKUs, value-added processing such as private labeling, and whether you are handling piece pick, case pick, or full-pallet loads are all factors that will affect your decision on a method for order picking.  Many times a combination of picking methods is needed to handle diverse product and order characteristics.

Key objectives in designing an order picking operation include increases in productivity, reduction of cycle time, and increases in accuracy.  Often times these objectives may conflict with one another in that a method that focuses on productivity may not provide a short enough cycle time, or a method that focuses on accuracy may sacrifice productivity.

• Productivity.  Productivity in order picking is measured by the pick rate.  Piece pick operations usually measure the pick rate in line items picked per hour while case pick operations may measure cases per hour and line items per hour.  In pallet pick operations the best measure is actual pallets picked per hour.  Since the actual amount of time it takes to physically remove the product from the location tends to be fixed regardless of the picking method used, productivity gains are usually in the form of reducing the travel time.
• Cycle Time.  Cycle time is the amount of time it takes to get an order from order entry to the shipping dock.  In recent years, customer’s expectations of companies to provide same day shipment has put greater emphasis on reducing cycle times from days to hours or minutes.  Immediate release of orders to the warehouse for picking and methods that provide concurrent picking of items within large orders are ways to reduce cycle times.
• Accuracy.    Regardless of the type of operation you are running, accuracy will be a key objective.  Virtually every decision you make in setting up a warehouse will have some impact on accuracy, from the product numbering scheme, to the design of product labels, product packaging, the design of picking documents, location numbering scheme, storage equipment, lighting conditions, and picking method used.  Technologies that aide in picking accuracy include pick-to-light systems, counting scales, and bar code scanners.  Beyond the design aspects of an order picking operation, employee training, accuracy tracking, and accountability are essential to achieving high levels of accuracy.

Piece Picking

Piece-picking methods.  

Piece picking, also known as broken case picking or pick/pack operations, describes systems where individual items are picked.  Piece pick operations usually have a large sku base in the thousands or tens of thousands of items, small quantities per pick, and short cycle times. Mail order catalog companies and repair parts distributors are good examples of piece pick operations.

• Basic order picking.  In the most basic order-picking method, product is stored in fixed locations on static shelving or pallet rack.  An order picker picks one order at a time following a route up and down each aisle until the entire order is picked.  The order picker will usually use some type of picking cart.  The design of the picking flow should be such that the order picker ends up fairly close to the original starting point.  The picking document should have the picks sorted in the same sequence as the picking flow.  Fast moving product should be stored close to the main cross aisle and additional cross aisles put in to allow short cuts.  Larger bulkier items would be stored towards the end of the pick flow.  This basic order picking method can work well in operations with a small total number of orders and a high number of picks per order.  Operations with low picks per order will find the travel time excessive in this type of picking and operations with large numbers of orders will find that the congestion from many pickers working in the same areas slows down the processing.
• Batch picking / Multi-order picking In batch picking, multiple orders are grouped into small batches. An order picker will pick all orders within the batch in one pass using a consolidated pick list.  Usually the picker will use a multi-tiered picking cart maintaining a separate tote or carton on the cart for each order.  Batch sizes usually run from4 to12 orders per batch depending on the average picks per order in that specific operation.  Batch picking systems may use extensive logic programmed to consolidate orders with the same items.  In operations with low picks per order, batch picking can greatly reduce travel time by allowing the picker to make additional picks while in the same area.  Since you are picking multiple orders at the same time, systems and procedures will be required to prevent mixing of orders.  In very busy operations, batch picking is often used in conjunction with zone picking and automated material handling equipment.  In order to get maximum productivity in batch pick operations, orders must be accumulated in the system until there are enough similar picks to create the batches.  This delay in processing may not be acceptable in same day shipping operations.
• Zone picking. Zone picking is the order picking version of the assembly line.   In zone picking, the picking area is broken up into individual pick zones. Order pickers are assigned a specific zone, and only pick items within that zone.  Orders are moved from one zone to the next as the picking from the previous zone is completed (also known as "pick-and-pass").  Usually, conveyor systems are used to move orders from zone to zone.  In zone picking it’s important to balance the number of picks from zone to zone to maintain a consistent flow.  Zones are usually sized to accommodate enough picks for one or two order pickers.  Creating fast pick areas close to the conveyor is essential in achieving high productivity in zone picking.  Zone picking is most effective in large operations with high total numbers of skus, high total numbers of orders, and low to moderate picks per order.  Separate zones also provide for specialization of picking techniques such as having automated material handling systems in one zone and manual handling in the next.
• Wave picking.  A variation on zone picking and batch picking where rather than orders moving from one zone to the next for picking, all zones are picked at the same time and the items are later sorted and consolidated into individual orders/shipments.  Wave picking is the quickest method (shortest cycle time) for picking multi item orders however the sorting and consolidation process can be tricky.  Operations with high total number of SKUs and moderate to high picks per order may benefit from wave picking. Wave picking may be used to isolate orders by specific carriers, routes, or zones.

Basic Order Picking Total Orders:       Low Picks Per Order:  Moderate to High   Batch Picking    Total Orders:        Low to High Picks Per Order:  Low   Zone Picking    Total Orders:       Moderate to High Picks Per Order:  Low to Moderate   Wave Picking    Total Orders:       Low to High Picks Per Order:  Moderate to High  

Piece-picking equipment: 

As with the picking methods, the picking equipment used will also depend on a variety of factors.

• Static shelving.  The most common equipment for storage in piece pick operations, static shelving is designed with depths from12” to24”.  Product is either placed directly on the shelving or in corrugated, plastic, or steel parts bins.  Static shelving is economical and is the best method where there are few picks per SKU or where parts are very small.
• Carton flow rack.  Carton flow rack is similar to static shelving with the exception that rather than shelves, there are small sections of gravity conveyor mounted at a slight angle.  Product is stocked from the rear of the flow rack and picking is done from the face.  Product can be stocked in cartons or small totes or bins. As a carton or tote is emptied, it is removed from the rack and another one will roll into place.  Carton flow rack is most useful where there is a very high number of picks per SKU. 
• Carousels.  Horizontal carousels are a version of the same equipment used by dry cleaners to store and retrieve clothing. They have racks hanging from them that can be configured to accommodate various size storage bins.  Generally an operator will run2 to4 carousels at a time avoiding the need for the operator to wait while one unit is turning.  Picking is usually performed in batches with orders downloaded from the host system to the carousel software.  Horizontal carousels are most common in picking operations with very high number of orders, low to moderate picks per order, and low to moderate picks per SKU.  Horizontal carousels provide very high pick rates as well as high storage density.   Pick-to-light systems are often integrated into carousels. Vertical Carousels are frequently used in laboratories and specialty manufacturing operations and are rarely used in regular order picking operations.
• Automatic storage and retrieval systems (ASRS).  An ASRS is a system of rows of rack, each row having a dedicated retrieval unit that moves vertically and horizontally along the rack, picking and putting away loads.  ASRS systems are available in mini-load types that store and transfer product on some type of tray or in bins, and unit-load types that transfer and store pallet loads or other large unitized loads. In addition to the automation features, ASRS units can provide extremely high storage density with capabilities to work in racking up to100 feet high.  Unfortunately the high costs of ASRS equipment and the length of the retrieval times make it difficult to incorporate into a piece picking operation.
• Automatic picking machines.  Fully automated picking machines (such as A-frames) are still pretty rare and are used only where very high volumes of similar products are picked such as music CDs, or,  where high volume in combination with high accuracy requirements exist such as pharmaceutical fulfillment.
• Pick-to-light.  Pick-to light systems consist of lights and LED displays for each pick location.  The system uses software to light the next pick and display the quantity to pick.  Pick-to-light systems have the advantage of not only increasing accuracy, but also increasing productivity.  Since hardware is required for each pick location, pick-to-light systems are easier to cost justify where very high picks per SKU occur.  Carton flow rack and horizontal carousels are good applications for pick to light.  In batch picking, put-to-light is also incorporated into the cart or rack that holds the cartons or totes that you are picking in to.  The light will designate which order you should be placing the picked items in.
• Bar-code scanners.  Though very useful in increasing accuracy levels, bar-code scanners in a fast-paced piece-pick operation tend to become cumbersome and can significantly reduce your pick rates.  With proper training, tracking, and accountability, you can get very high accuracy rates in order picking without scanners.   I find they are better suited to case pick, pallet load, putaway, and order checking operations.
• Voice-directed picking.  Voice technology has come of age in recent years and is now a very viable solution for piece pick, case pick, or pallet pick operations.
• Automated conveyor and sortation Systems.  Automated conveyor systems and sortation systems will be integral to any large-scale piece pick operation.  The variety of equipment and system designs is enormous.

Systems of Order Picking and Assembly:

1.Area System

The order picker circulates throughout the warehouse selecting the items on the order, much as a shopper would in a supermarket.

2. Modified Area System

This system operates as the area system except that the working stock and the reserve stock are separated.

3. Zone System

The warehouse is broken down into zones and each order picker (or group of pickers) works only in his or her own area.

4.Sequential Zone System

The order is broken down into zones and then passed from zone to zone as it is picked.

Best regards