6-Order Picking & Assembly PDF

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Picking process mercoledì 18 ottobre 2017 12:49

Picking: selective retrieval of unit loads from high level unit loads or single pieces/cases from racks or plastic crates in order to fulfill customer purchase orders. We need to pick when the amount of goods required is smaller than the pallet size Order assembly: one of the phases of the order-delivery cycle. We can describe the customer order as a set of items required by the customers, looking not only at the number of items but also at the number of pieces

Order line: number of items required by the customer (in the example 3 order lines) PICKING LIST PRODUCTION (1) Picking list (warehouse order): it is a list of pick locations, items to be picked and quantities to be picked. Crucial for the efficiency of the picking process. The sequence is chosen with the aim of optimization of the picking process. We have 3 managerial options to create the picking list. 1. Order picking. One customer order assigned to one warehouse order.

2. If the size of the order is so big that we can't pick everything at the same time you can split the customer order 1 in a first warehouse order (1.1) then in a second warehouse order (1.2) . Where every warehouse order represents a part of the customer order. Order picking

6. ORDER PICKING & ASSEMBLY

3. Last case. Aggregate different customer orders to one warehouse order. Batch picking.

PICKING (2) Picking: the process by which single pieces are assembled in boxes/cases (secondary packaging) and the boxes/cases are weighted and labeled and/or boxes/cases are assembled into Unit Loads (tertiary packaging) SORTING (3) Sorting: process through which the goods are divided according to their destination. Required only if the goods have been picked in "batch" PACKAGING (4) It depends on the type of picking. • Pieces picking: it is required. Wrap the pallet using a film. TRANSPORT LOAD CONSOLIDATION (5) Final check then shipment of goods. Transport load consolidation: the process through which the Unit Loads (for single customers or single destination) are assembled into a Transport Load, including also the final check and the matching with the shipping note. Why is picking important? • Very expensive - 50% of the overall cost of warehouse - The most important component for the picking activity is the picker travel. We have to minimize the travel in order to minimize the cost of picking process • Impact of the service - Order cycle time - Delivery accuracy and flexibility

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Why is it so expensive? • In case of pallet handling we are moving more cartons at the same time and we can assume: - 1 pallet -> 50 cartons - Cost of 1 cycle: 2€/pallet ▪ •

In case of picking we can assume: - Productivity: 100 cartons/hours - Labor cost: 20€/hour ▪

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In case of picking the cost is 5 times greater than the handling cost for pallet handling!! Also higher complexity in terms of moving goods

General trends We have new trends that are growing nowadays for example: • Enlargement of the product assortment • Increase in the delivery frequency If we merge together this two trends the result is the decrease of average quantity per order. This is translated in an higher complexity and costs of picking and order assembly activities

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Picking systems mercoledì 18 ottobre 2017 13:27

We can find a lot of solutions in the market and we can classify the order picking solutions based on 5 main decision: 1. Who picks goods • Human • Machines - Automated picking system 1. Dispenser 2. Robot 2. Who moves in the picking area • Pickers: the pickers move to the goods • Goods: the pickers stay in a fixed location waiting for the goods coming in the storage area - Parts to picker system 3. Subdivision of picking area in zones and use a conveyor • Yes - Pick to box system - Pick and sort system • No - Picker to parts 4. Picking police • Pick by item (batch picking) - Pick and sort system • Pick by order (order picking) - Pick to box • Pick by item/order - Pick to parts For every system you find in the market different technologies and configuration We can evaluate the different solutions in terms of: • Investment costs • Productivity • Space cost • Flexibility • In terms of picking capacity of the system • Accuracy

6. ORDER PICKING & ASSEMBLY

Picker-to-parts Most used system. The picker carries out a “picking mission” within the “picking area”, visiting in sequence all the locations which are detailed in the “picking list"

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The yellow parts represent the picking location The blue parts represent the locations to be visited The lines represent the travel I/O is the start and end location for every travel. The same for start and end - Input: the picker takes the empty pallet and the picking list - Output: the picker unloads the pallet

Configuration The possible configuration are the of combination • Storage system - Large size unit loads ▪ Selective pallet racks ▪ Flow racks - Small size ▪ Shelves/bins ▪ Flaw racks ▪ Drawer • Handling equipment - Motor driven order picker trucks - Manual driven order picker trucks 1. Manual picking on an order picker truck with picking aisle • Goods placed at ground level • The replenishment is done by the upper-level pallets • Goods placed in a roll container or on the forklift • Drawback - The maximum number of items managed in the picking area is equal to the number of pallet at the first level. ▪ Solutions ➢ Liftable platform forklifts ❖ Benefits in terms of SKU in the system ❖ But you lose in picking productivity (risk of falling) ❖ Safety issues

6. ORDER PICKING & ASSEMBLY

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Narrow-aisle turret trucks ❖ Instead lifting the picker to 1 meter it lifts the picker to 12 meter ❖ Same drawbacks of liftable platform ❖ Also the fork can be lifted for the ergonomicity of the workers ❖ Very dangerous! ➢ Reduce the size of picking location ❖ We can manage an higher number of items ❖ When you need picking location the best solution is to modify the picking location 2. Picker drives an Order Picking Truck (low level) or a manual Picking Cart • We have cartons not pallets • We retrieve pieces from cartons • We can have different racks - Flow racks

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Mezzanine

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Dedicate at least one channel for an item Benefits - Managing an higher number of item - Better for class-C items - Increasing the picking density

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Drawback - Store smaller quantity of an items ▪ Higher replenishment cost - Impossible to reach higher level using shelves ▪ We can solve this issue using a mezzanine, two levels of shelves ▪ eCommerce B2C uses mezzanine

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3. Picking on automatic S/R machines • Not used anymore - Very slow - Impossible two go fast - Old technology - Picker doesn't know the direction • Not liked by Melacini • The picker is moved by a machines

Part-to-picker It tries to solve the problems of picker-to-parts. The pickers stay in a fixed location waiting for the goods. The pickers receive the UL and retrieve just the needed quantity and then the UL return to the storage area. The movement from the storage area to the picking station is proportional to the order lines. There is an implementation of automated solution that can be classified by the size of UL: • Large size UL - Picking from automated warehouses to picking bays ▪ From S/R machines to AGV/conveyors/forklift trucks then to picking bay

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Used in Perfetti Van Melle ➢ We place 30/40 locations outside the automated warehouse due to the need of continuous feeding of the picking station and doing that you can reduce number of movements for the S/R machines ❖ We have to choose the type of items stored outside the automated warehouse ✓ Class-A items In order to minimize the picking cost is important the capability of the system of feeding the picking station so the idle time of the picker is optimized

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Small size UL - Miniload AS/RS - AVS/RS (Autonomous Vehicle Storage and Retrieval System) - Vertical carousel (horizontal axis) - Horizontal carousel (vertical axis) - Automatic vertical storing system

SMALL SIZE UL • Miniload AS/RS - Name of automated warehouse for cartons or totes - It works in the same way as the automated warehouse - Differences ▪ We do not have the rack-supporting building ▪ Max height: 12 meter ▪ Length: 40-60 meter ▪ Very fast ➢ 200 moves/hours ▪ Maximum size of the tote: ➢ Base: 0.4 x 0.6 meter ➢ Height: 0.4 meter ▪ Very expensive ➢ 500 000 € ▪ Maximum weight: 15 kg ▪ High AUR - Different configurations ▪ Pickers visit different aisles ➢ Needed slow picking activity ▪ Manual picking station ➢ Connected to the storage area by the use of a conveyor ➢ The blue tote represents the item ➢ Yellow tote represents the customer order ➢ Order-picking policy ❖ Preparing one order at the time ➢ Then the items return to the AS/RS ➢ Difficult to understand the right position of picking station ➢ Trade-off between ❖ Long aisles and long cycle time ❖ Small system with longer and higher aisles having few aisle and few S/R machines ▪ Batch picking policy ➢ Reduce the number of movements ➢ Reduce TC requirements ➢ Reduce investment costs

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AVS/RS - We substitute the

Expensive solution but more performing Vertical and horizontal carousel - Less expensive but also less performing - Pickers in front of the system - Very slow (15 cycle/hour) - Picker works using two carousel at the same time - Not common - Horizontal carousel ▪ Vertical axis ▪ 2 meter height ▪ 14 meter length - Vertical carousel ▪ Horizontal axis -

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Automated vertical storage system - The lift inside the carousel takes the tray and gives it to the picker - Fast - Dual command cycle - Expensive but not so much ▪ 70 000 € - You can put this solution wherever you want in your warehouse - Slow moving items - Storage of components and kits ▪ Ducati

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Pick to box (pick and pass) You subdivide the picking area in zones where the size of each zone is equal and you assign one or more picker to each zone. The picker can work only within the zone. Then we introduce a conveyor to connect the different zones fed with empty cartons or totes. Every bin stops at the picking station where at least one item has to be retrieved then the tote returns to the conveyor and stops at the next picking station. Different totes or cartons correspond to one customer order. At the end of conveyor the totes are sorted by destination Also called progressive zones due to the visit in sequence of the different zones. High difficulty of balancing the work load among the zones, this is the main risk. Higher risk with higher number of zones and picking zones.

PICK TO LIGHT We use the light to drive the picker and we place light displays in every picking location when an items has to be retrieved from a specific picking location the light is illuminated. Very fast to recognize the light. We are working on the fixed time.

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Pick and sort Subdivide the picking area in zones but size of each zone is variable not fixed. Each area to one picker. The size depends on the workload and generation of warehouse order. Batch picking policy, we aggregate all the others and we create the warehouse order, very big, so we split it in suborders. The key point is to put all the pieces required by the aggregate customer order and located in nearby location. We can have 5-6 items in one suborder. So it's clear that the zones depend on the size of the order and location of the goods. Then the suborder is placed on a takeaway conveyor that brings the suborder to a sorting machines that sorts the items by customer order. Wave: launch of new warehouse order. Pick to belt: It is possible to have a belt conveyor that feeds the main conveyor. You pick the goods and you put in the main conveyor.

It's possible to work without conveyor and we only have the picking area, sorter and induction station.

6. ORDER PICKING & ASSEMBLY

Several, different technologies are available for automated sorting systems. The choice between the different discharge mechanisms is based on amount of goods to be sorted and the physical dimensions of the items to be sorted and is influenced by factors such as the weight, size, and fragility of the items. The choice depends on the capacity of the sorter and the cost of it (minimum 2'000'000€) and on the fragility of the items. The most performing sorters are: • Cross-belt system: - 90° oriented respect the direction of the sort - This system can discharge the items both left and right

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Tilt-tray system - We have a set of trays and they reach the line where to discard the good, it's is sufficient to tilt the tray

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Automation of manual picking We can automate the communication between the WMS system and the operators • Automatic identification of the items - Bar Code Scanning

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Radio Frequency Identification (RFId) ➢ Low accuracy in reading multiitem pallets

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Radio Frequency Communication between the Warehouse Management System and the pickers - Mobile devices aboard the picker trucks - Hand-held mobile devices (terminals, headphones, finger-wearable, …)

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Display and lights on the picking locations - Putted on locations that represent customer order - We perform a batch picking where we retrieve all the pieces Scale to check the number of items (on the picker truck, on the picking station) - Weight the goods at the end of the picking Voice Headsets and Visual Picking Technology - Communication by voice ➢ We avoid the scanning of bar codes and we can work hand free ➢ Improve 10/15% in picking activity

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Use smart glasses to drive the pickers ➢ Very far from real implementation ➢ Lot of issues

Automated picking Dispenser and robots. Dispenser: set of verticals channels where we put the goods, and at the basis there is a conveyor. During the picking activity the items in the channels are pushed on the conveyor that carries the items to a tote that represents the customer order. AUTOMATIC DISPENSERS • Replenishment activity is done by workers - High labor cost due to this replenishment ➢ To minimize this costs we have shelves with the goods near the dispenser - The replenishment cost is higher than the picking cost • Very expensive • Low capacity of the channels • Small, regular, non-fragile, high-demand items • High retrieving capacity: up to 3000 pieces/hours • Used just in specific cases - Distributors of medicines - Cigarette producer • A-Frame

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V-Frame

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ROBOTS • Anthropomorphic robots - Instead of using workers we use robots - Not the future, it is quite common

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Cartesian robots - Carroponte in Italian - It moves in along the 3 axis - Take the cartons from different pallets and put them on the mixed pallets

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Sum-up Terms of analysis

Picker-to-parts

Part-to-picker (Miniload)

Pick-to-box

Pick and sort

Investment Costs

Low: only the cost of

High

Medium: just the cost of the conveyor

Very high: average cost of sorter is 2M

Productivity

Low: we lose time for the lifting of the picker

High: picker fixed in one location. Minimize the picking time

Medium: improvement of the productivity due to the reduction of the moves

High: slightly smaller than part-to-picker but the value is high

Space Cost

Medium: it depends Low: it depends on Medium-High: no on the type of the size of the picking height development solution adopted station, but good exploitation in height for the system

Very high: main drawback of the sorter, the sorter occupies space

Flexibility

High: we can change Low: typical disposition and add disadvantage of the pickers automation

Medium: easy to modify the system

Medium: always possible to modify the sorter, adding lines

Accuracy

Low-Medium: it depends on the quality of pickers. We can use technology to control the performance (barcode)

High: the tote stops only at the right picking station

High: 2 controlling point: inductions station and at the beginning

High: the picker receives only the right item, other control is weight the created pallet and compare it with the weight of the theoretical pallet

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OPS design martedì 24 ottobre 2017

3 main decisions 1. Selection of the picking system 2. Picking system capacity and design • Layout of the system 3. Management policies • Try to optimize the performance of the system

KEY PERFORMANCE INDICATORS You have to compare the different solutions in terms of cost and impact on the customer service. Picking-related costs • Picking costs (people, equipment, software and space) • Sorting costs (people, equipment, software and space): only when I have to sort the goods • Replenishment costs (people, equipment, software and space) Customer service • Accuracy • Order picking cycle time • Flexibility ORDER PROFILE It is important to understand the features of customer order We can express the characteristic of customer order using the order size. • Order profile based on volumes (lines/order)

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Order profile based on volumes (volume/order)

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Order profile based on the picking unit

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Order profile based on volumes ( % palletized ULs) - Express the size as a percentage of one palletized Uls

Selection of the picking system (1) The identification of the best solution is a result of economic analysis, but is possible to reduce the number of possible alternatives looking at 3 main factors: 1. Characteristic of the order (order line/volume) • Small - e.g. the order size is smaller than 0.5 m3 • Large 2. Storage capacity • Number of SKU managed by the picking system 3. Picking capacity requirements • Number or order lines per day

Order size < 0.5 m3 • Number of items - < 1000 ➢ Picker-to-parts systems ▪ Just looking at the number of items we choose this system • High storage capacity relative to the number of order lines per day - Parts-to-picker systems ➢ With picker to parts we lose productivity due to the length of the travel • 1'000 < order lines/day < 100'000 - Pick-and-pass system

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Order size > 0.5 m3 • Picker-to-parts systems is the best solution - Allows the subdivision of one customer order in smaller sub-orders and each sub-order is assigned to a different picker • Parts-to-picker systems - Significant number of items and not high requirement in term of picking capacity

Picking system capacity and design (2) STORAGE CAPACITY (SC) • Number of Unit load locations (with dimensions: a x b x h and a determined weight capacity) THROUGHPUT CAPACITY (TC) • Number of Orders per hour/day • Number of Line items per hour/day • Number of boxes/cases/pieces per hour/day • Volume Flow per hour/day We need to solve the forward-reserve problem in order to assign the right storage capacity. • How to split the overall inventory within the warehouse into a reserve stock and a forward stock (= inventories dedi...