Order Picking Methodology

Warehouse Management is a key factor in Supply chain management, hence let's understand few aspects of warehouse management. Order assignemnt policy is the most importatnt aspect in warehouse management because order picking is the costliest operation in inventory management. 

Order Picking- Retreiving products from storage area for shipping them in a different unit size. 

• Labour intensive
• 55% of warehouse operating cost 
• It should be accurate
• Direct influence on the delivery time

Types of picking-

• Pallet picking
• case/box picking
• piece picking

Picking Method

• Low Level Picking
• High Level Picking
• Station Picking

There are four different Order Assignment Policies-

1) Strict Picking (Descrete Picking)

2) Batch Picking (Line Picking)

3) Zone Picking

4) Wave Picking

1) Strict Picking

It is a strategy in which a picker completes only one order at a time. We will aplly this picking as the order sizes we assume to be relatively large.

Advantages-

• Order integrity is maintained
• A complete order arrives in shipping, usually picked by a single worker
• No downstream sorting

Disadvantages-

• Effective in case of small quantities of orders to be picked

2) Batch Picking (Line Picking)

    The worker selects item for several orders at a time

    If the orders are small and we have enough picking capacity, a set of orders can be picked in a single picking tour.

    A saving on the travel distance can be obtained by combining a set of small tours into a smaller set of large tours.

Advantages-

• Multiple order completion in one tour

Disadvanted-

• Effective only when orders are not big
• Sorting is required downstream to consolidate orders

3) Zone Picking

    Each worker is assigned a zone

    It is also possible to divide the order picking area into zones

    Each SKUs belonging to the same product group are then stored close to each other

    Order pickers are assigned a specific and physically defined zone in the pick area

Zoning might be advantageous as each order picker only needs to traverse a smaller area

Reduce aisle congestion and also order picker becomes familiar with the item locations in the zone

Drawback of zoning is that orders are split and must be consolidate once again before they are shipped to the customers

This is typically referred to as "Pick and pass" methodology

Advantages-

• Travel distances are reduced drastically
• Each order picker only needs to traverse a smaller area

Disadvantages-

• Unnecessary transport activity when cart passes through non required areas

4) Wave Picking

    As the name implies, orders are consolidated into waves of work . An advantage of this method is         that waves can be created based on rules tailored to meet the needs of the moment.

Wave picking is very similar to discrete picking in that one picker picks one order, one SKU at a time. The main diference is the scheduling window. In discrete picking , there is not a scheduling window whereas in wave picking there is.

Orders may be scheduled to be picked at specific times of the day, which is usualy done to coordinate and maximize the picking and shipping operations.

Advantages-

• Waves can be created on the basis of pre-defined rules to meet tailored needs

Disadvantages-

• Comparatively complex to manage