Warehouse order picking is a core function in warehouses and distribution centers, accounting for the majority of operating costs, with an outsize impact on customer service and satisfaction.
Picking errors in manufacturing warehouses can slow-down production lines, while inefficient order picking in DCs weighs down profits. Adding to the cost pressure, companies like Walmart and Amazon are forcing other retailers and distributors to adapt to free one day or same day shipping.
Beyond the cost and service imperatives to improve order picking, warehouse managers are also dealing with a scarcity of qualified workers in many areas. Competition to recruit workers has become especially fierce over the past several years as companies have built massive new ecommerce facilities to meet growing demand.
This warehouse order picking introduction is meant to help outline best practices and strategies for optimizing picking based on the collective experience of the Lucas team.
We’ve attached a variety of resources to help you learn more about each topic. If you have any other questions about specific solutions or specific picking types, please contact us.
What is Warehouse Order Picking?
Order picking is one of the key stages in the supply chain. By definition, picking orders is a simple concept, but in reality it can be very complex.
Warehouse order picking involves getting a product from warehouse inventory into the hands of the consumer.
If you currently operate a warehouse or distribution center fulfilling orders and deal with speed, accuracy, organization and labor issues there are many different ways to improve picking processes. Streamlining current processes by investing in technology and developing picking strategies can lead to:
- Double-digit reduction in errors. (Learn more by reading our blog, “How to Improve Order Picking Accuracy”)
- Reduction in training from two weeks to two days.
- Improved employee moral with reduced turnover.
- Double digit increases in productivity rates. (Learn more by reading our blog, “The Ultimate Guide to Improving Warehouse Order Picking Productivity”)
What Are the Different Picking Types?
Warehouse order picking processes and strategies can vary depending on the facility type (production warehouse, distribution center or ecommerce fulfillment center) and product type. Regardless of whether a facility is picking pallets, cases, or individual items (or eaches), there are four main picking strategies.
There are four main order picking strategies
1) Discrete Picking
This is the most common type of order picking because it is very basic. Discrete picking involves one picker picking an entire order. A picker will move throughout the entire warehouse and pick up the various parts of an order before returning to the staging area for the order to be shipped. Discrete picking is used primarily by warehouses using a paper based picking system. The system may be simple, but isn’t always the best strategy for the current distribution market demands.
2) Zone Picking
Pickers are assigned to a specific area in a warehouse. They are responsible for picking all of the SKUs located in that zone for every order. Zone picking is a way to reduce travel for pickers because they are staying in a certain area and passing the order outside of their zone to the other pickers.
3) Batch Picking
Batch picking (which is also referred to as cluster picking) is a strategy for work execution in which workers pick multiple orders on each trip through a distribution center or zone within the DC. So, rather than making two discrete trips through a DC to pick two orders, a single picker can pick a batch of two orders on one trip, cutting travel in half.
4) Wave Picking
Wave picking is a common method of creating discrete groupings of orders (waves) that are released in sequence (wave 1 followed by wave 2, etc.) for picking throughout a shift or work day. It is an efficient way for DCs to organize and process large business-to-business orders and to manage DC throughput. Each wave of work typically represents one or more hours’ worth of work for picking, packing and shipping, based on the capacity constraints of the DC (for example, the number of loading doors, sorter capacity, etc.). Waving is a standard capability in most warehouse management systems.
What Are Some Tools Warehouse Leaders Use to Help Optimize Your Warehouse Processes?
Aside from basic warehouse order picking types there is also a lot of equipment and technology available to help optimize picking processes. These solutions include voice picking, RF scanners, robots, smart glasses for “vision picking” and more recently AI and machine learning.
1) Voice Picking or Voice-Directed Warehousing
Voice picking is a proven process for increasing efficiency and accuracy of pickers in warehouses or distribution centers. Here’s a brief overview of how it works:
- Pickers wear headsets with an industrial microphone that connects to a mobile device running the voice application.
- The voice of the application tells the picker where to go and what to do, such as the warehouse pick location to go to and the quantity of the item to pick. The picker speaks into the microphone to confirm their work.
- The voice picking application includes speech recognition software that recognizes and interprets the order picker’s spoken responses.
- Pickers confirm they are picking the correct item by speaking a checkstring to validate the picking location. Or, in some applications, they may speak several digits of a product code or other ID printed on the product.
- Pickers also confirm the quantity being picked. The voice application will correct the picker if they enter incorrect information.
As the phrase “voice picking” suggests, organizations initially used these solutions to improve picking operations with voice-only technology. However, today’s voice-directed applications often incorporate complementary technologies like barcode scanning or RFID.
Furthermore, they now help automate any manual, hands-on process in the warehouse. For example, receiving, put away, replenishment, cycle count, sortation, packing, cross-dock, loading, etc.
2) RF Scanners
RF refers to warehouse operations systems in which workers access their work instructions on a wireless mobile computer (wearable, hand held, or vehicle mounted) that integrates with a host or warehouse management system (WMS) over a WiFi network (radio frequency, to borrow a term from the 1990s).
A typical RF scanning system provides text pick instructions on a computer screen. Pickers confirm their tasks by scanning barcodes on product or shelf locations, and by key entering information or pressing function keys on their mobile computer. Many older RF systems use terminal emulation software (TE) running on the mobile computer. TE is a technology that translates applications and information that was originally designed for use on a desktop “terminal” to be used on a mobile computer. TE is commonly used with older warehouse management systems and custom developed mainframe or host computer systems. (It is still common to hear warehouse operators refer to a mobile computer as an RF terminal, a nod to terminal emulation.)
3) Robotic Solutions (AMRs, ASRS, Etc.)
In order to answer both the speed and scarcity of warehouse workers, robots have made an appearance into many different warehouses and DCs. The addition of machine learning and artificial intelligence helps increase the intelligence of robots allowing them to work side by side with humans. There are multiple different kinds of robots that can help assist in warehouse order picking processes:
- Automated Guided Vehicles
- Autonomous Mobile Robots
- Aerial Drones
- Automated Storage and Retrieval Systems
4) Smart Glasses
The concept of “vision picking” with smart glasses is that order pickers in a warehouse or DC can view pick information within their field of vision, rather than looking down at a mobile RF terminal device screen. To confirm their tasks, workers can capture barcodes using the camera embedded in the wearable glass frame rather than handling a scanner. Equally important as the display and scan capabilities, smart glasses include speakers and microphones so that workers can interact using voice direction and speech recognition.
With a heads up display, the user can glance at information to the side of his main field of view. Product images, visual indicators and textual information can be displayed based on context or user request.
Task information is presented to workers in the form of text and images available in the user’s field of vision on a wearable “heads-up display.”In essence, vision picking merges best available mobile technologies:
- Verbal prompts and instructions supplement and complement the text and visual information.
- Users can scan barcodes and use voice commands to confirm their activities without stopping to handle and aim a handheld scanner or key enter information.
- Finally, workers can request help, report exceptions, and navigate the application workflow (skip item or aisle, change work area, etc.) using voice commands.
However, today’s smart glasses are for vision picking do not provide augmented reality or vision recognition, two key capabilities that will add significant value beyond current wearable technologies.
4) AI-Based Optimization
Aside from voice picking, RF scanners, robots and smart glasses, artificial intelligence and machine learning are two emerging technologies that are becoming necessary to optimize and further improve end-to-end warehouse operations.
AI-based algorithms help transform distribution operations by:
- Orchestrating and optimizing resources – people, robots, inventory – across IT and automation systems.
- Enabling managers to make slotting moves ahead of changing conditions with dynamic slotting.
- Reducing picking travel through intelligent batching and path optimization.
- Providing predictive workforce planning and performance management capabilities.
How to Determine Which Strategy Is Right for You
Conduct an operations assessment
A good way to get started in developing a vision for that end-state, and for projecting the potential efficiency benefits of new picking methods or technologies, is to conduct an operations assessment.
Similar to a lean assessment as part of a six-sigma process, you will need to document how and why you are doing things today to identify specific time-saving opportunities in your existing process.
Beyond the possibilities for process optimization, the assessment exercise will typically suggest new ways to better achieve your business and operational goals – it forces you to think beyond “this is how we do things” to “this is why we do things.”
Lucas Offers an Operations Assessment Service to Help Identify Process Improvement Opportunities
To help DCs conceptualize their own optimal process – and to begin to estimate your end-state productivity, accuracy, throughput, etc. gains – Lucas offers an operations assessment service. The purpose of the assessment is to identify specific process improvement opportunities in your facility.
Many of the process improvement ideas that come out of the assessment will involve the application of new technologies (voice, scanning and device displays, etc.) in a new user workflow, along with other optimization technologies (such as batch algorithms and pick-path optimization engines). In some cases, process improvements can be implemented with no change in picking technology, but voice and other new technology (RFID, pick to light, etc.) may compound the benefits of any process changes.
This exercise takes some time, but it is time well spent. The assessment allows you to consider how new optimization technologies and workflow solutions can impact productivity beyond the efficiency gains of voice at the pick face. Taking this approach can translate into hundreds of thousands of dollars in annual labor cost savings. Get started by contacting us today.