Embed Size (px)
Citation preview
The Waveless Warehouse: Why Wave Picking Might Not Be the Best for Your Distribution Center
White Paper
www.viastore.com · [email protected]
2
What is Waveless?
Why Waveless?
Foundational Elements
What is ‘WES’ and Why You Need It
Contents
Putting it All Together
www.viastore.com · [email protected]
3
We adopt new technology because it presents a better way of getting things done. The horse and buggy gave way to the car because of speed and convenience. The smart phone eclipsed feature phones because consumers could have richer apps and a connected experience.
Similarly in business, new technology must bring tangible benefits to really catch on. A new buzzword won’t cut it without bottom line benefits, especially in the cost conscious world of logistics.
Within warehouses and distribution centers (DCs) one buzzword that has been around for a few years is “waveless” picking. While waveless operations have been adopted by a few U.S. companies, and are much more commonplace in Europe, the characteristics of waveless picking, its benefits, and its supporting elements, are far from well understood. But if your DC is beset by bottlenecks, poorly coordinated islands of automation, and is struggling with the tighter order priorities common to multichannel fulfillment, then it may be time to learn more about waveless picking and what it can do for your bottom line.
The best way to understand waveless is to consider the evolution of wave picking. A ‘wave” is a grouping or batch of work released for picking based on common parameters.
A wave may be organized around common stock keeping units (SKUs), commonality in
the locations SKUs are stored within, shipping deadlines, common carriers, and common
sorting or kitting processes the batch of work needs to flow through. Grouping work
into waves caught on because it tends to be more efficient than strict order line picking
in which individual orders entering the system are picked by a single picker. With waves,
picker travel time is reduced, leading to better efficiency than picking orders one at a time.
There are problems with wave picking, however. Waves generally are processed in a
serial fashion, meaning workers and equipment must wait to finish one wave before
they move on to the next. While it might be possible to process some waves
simultaneously, the availability of sortation, other equipment or processing areas
might limit the ability to process more than one wave concurrently.
What is Waveless?
www.viastore.com · [email protected]
4
This batch nature of wave picking leads to other problems, including:
• There is usually no ability to accommodate high priority picks and tasks once a wave is established and set in motion without manual expediting.
• During the start and middle of a wave, pickers, packers, and islands of automation usually stay busy, but during the tail end of a wave, one process often finishes before the others, leading to idle time and starts and stops at points in the workflow.
• While more efficient than strict order picking, the batch nature of waves inherently limits the picks, tasks and processes that potentially could be worked on.
• Adding additional “similar” work to the wave is not possible or is a very manual process.
There is another, more continuous way, to handle order releasing. It’s gained
the name ‘waveless’ because rather than batching work together in a wave,
orders and items are constantly released to the floor for processing in a
continuous flow of work. Waveless requires real-time knowledge of equipment
status and configurable software intelligence to dynamically assign tasks and
manage the flow of work, but once established, it offers a highly flexible way to
keep a steady, busy flow of work moving through the DC and out to customers.
Why waveless?In a word, the key benefit of waveless is flexibility. Because work is not batched
together in a wave, any order, item, or task entering the system is available for
picking or other processing. This helps both throughput and efficiency. There is
greater throughput because the DC is able to accommodate high priority orders
on the fly, and doesn’t experience a diminished productivity curve at the end
of waves. And because waveless doesn’t put limits on what can be picked or
processed in other ways by considering only the pool of tasks within a wave, the
density of potential picks increases, which helps cut travel time. The result is that
pickers, packers and automated equipment can handle more tasks in less time.
Why Waveless?
www.viastore.com · [email protected]
5
The benefits of waveless picking go beyond a higher utilization of labor and equipment.
The flexibility allowed by waveless picking enables better throughput. For front line managers
and personnel, this means a steady, balanced flow of work that allows them to attain targets
for metrics such as orders picked per hour, while virtually eliminating the hassles of trying to
manually alleviate bottlenecks by methods such as rushing labor between locations or
opening up accumulation lanes.
From a senior management perspective, waveless picking is all about improved productivity
and throughput. Because waveless can accommodate priority orders and keeps the workload
productive and balanced, order cycle times improve. Getting more orders out the door with existing
resources also works to lower the cost per order, and total warehouse costs as a percentage of
sales. Done right, waveless picking allows you to do more with your existing resources,
while accommodating the increased order velocity and order mix of multichannel fulfillment.
www.viastore.com · [email protected]
6
Foundational elementsSo if all of these benefits are attainable with waveless picking, why isn’t everyone doing it?
Part of the reason why may be that U.S.-based DC operators simply are used to processing
work in waves. While wave picking has worked adequately at many DCs, it’s becoming tougher
to make waves work smoothly given the changing order requirements of multi-channel and
the addition of more automation in many facilities. Additional automation —without the right
layer of software to orchestrate material flow and communicate to the warehouse manage-
ment system (WMS) level—can become sub optimized “islands” of automation.
The other hurdle with going waveless is that it requires some key software elements spanning
the warehouse control system (WCS) layer and to some extent, at the WMS level, to provide
the intelligence and visibility to adjust to conditions on the fly.
Foundational Elements
www.viastore.com · [email protected]
7
Once you decide to go waveless, the main elements needed are twofold. First, you need a
Warehouse Execution System (WES). What’s a WES? The term warehouse execution system
(WES) has been used to describe the hybrid of WCS and WMS capabilities needed for today’s
dynamic fulfillment operations. WES is a tightly integrated combination of Warehouse
Management (WMS) and Warehouse Control (WCS) Systems that work in unison to execute
work throughout the entire distribution center, including picking, packing, automation, etc.
This allows for real time connectivity to all of a DC’s labor and automated material handling
equipment. The WES needs this real time visibility to orchestrate work and manage material
flow. Trying to connect multiple legacy control systems to a warehouse management system
(WMS) won’t be real time enough to smoothly coordinate waveless operations.
Secondly, The WES must have configurable rules to govern how the flow of work should be
dynamically processed. These rules are common sense parameters that operations can configure
in the WCS, such as how much work can be in process in a given work area, pack station, lane
or location. These rules act as thresholds to ensure a steady, continuous flow of work.
The WCS is constantly monitoring its real time grasp of material flow and equipment status
against these parameters to automatically determine the next best pick or task that should
enter into the workflow to optimize the overall operation. Think of the WCS’s function here
as more than a ‘traffic cop’ role—it’s really more like an orchestra conductor.
Examples of the types of parameters a WCS needs to be able to support as part of waveless
picking includes:
• Give next pick preference to new orders with a high delivery priority.• The ability to adjust the next picks entering the system based on thresholds being
reached at downstream locations or processes.• Limit the types of commands that can be released for processing within a given time
span, depending on the type of order.• Set a limit on how much work can be released to an area or location based on the
number of pickers or resources in that area or location, etc.• Give preference to a pick that would allow completion of an entire order, even if it’s
not a high priority order, if the system sees the order is close to being filled.• Dynamically group picks by similar configurable characteristics to further optimize picking.
In practice, these parameters need to be easy to establish. A WCS with fields that can be
filled in with numbers to set parameters, rather than via programming, is an important
consideration when looking for a WES to support waveless.
What is WES and Why You Need It
www.viastore.com · [email protected]
8
To make waveless more effective, it helps to have a WMS that can communicate with the
WCS at a granular level about all the details involved with inventory, orders and shipping.
The WCS and WMS also may need to communicate about other tasks besides picking, such
as packing, cycle counting or restocking, that can be dynamically managed by the WCS layer
as part of orchestrating the continuous flow of work. It also is important that the WCS is
able to communicate with the WMS and/or transportation management system (TMS) so that
the WCS knows when shipping is available. The idea is to optimize the overall flow of work
through the operation, including out to transportation.
Putting it all togetherThe heart of a waveless warehouse is a configurable WES with connections to all the
automated materials handling systems and programmable logic controllers (PLCs) that run
automated equipment in the DC, and ideally, has the capability to run the remaining manual
operations of the warehouse as well. Not all legacy WMS or WCS solutions are up to the task.
They might not be configurable enough, or perhaps they are purpose built for just one specific
manufacturer, area or type of automation.
So a modern, rules-driven WES is essential to waveless, but additionally, configuring the solution
typically requires an analysis of the shipping requirements of a DC, as well as analysis of the
equipment, labor resources, and material flow. The WES provider should be able to provide
such an assessment as part of its design process. While setting parameters may sound
complicated, experienced WES providers can rapidly assess the critical workflows in a DC and
help configure the rules that will provide the most benefit for optimal DC operations.
Selecting a WMS and WCS from different vendors to obtain an effective WES solution is a
risky proposition due to the requirements for tight, real-time, in-sync integration and
communication between the two systems.
Putting it All Together
CONCLUSION The end goal with waveless is a more productive DC—one that is able to pump out more orders and accommodate tighter delivery requests. Warehouses that transition from waves to waveless can expect to see steadier utilization rates because they won’t have idle labor or equipment as waves wind down. That’s the efficiency benefit of doing away with waves, but the bigger reason to consider waveless is the throughput potential. When you’re always working on the next best pick or activity as orchestrated by a WCS, you become more flexible, and that, in turn, leads to faster, more productive order fulfillment.
www.viastore.com · [email protected]
9
viastore systems is a leading international provider of automated material handling solutions
including automated storage and retrieval systems (AS/RS), conveyor and sortation systems,
warehouse management systems (WMS) software, warehouse and process controls, and integrated
SAP logistics solutions for new systems and for modernizing and updating existing systems.
The company employs over 450 people worldwide and has annual sales of over US$207 Million.
INTRALOGISTICS SYSTEMSn Automated Storage & Retrieval Systemsn Conveyor & Sortation Solutionsn Shuttle Systemsn Retrofits/Modernizationsn Services
INTRALOGISTICS SOFTWAREn Warehouse Management & Execution Systemsn SAP Logistics Solutions
viastore systems Inc.
4890 Kendrick SE
Grand Rapids, MI 49512
USA
Tel. 616 977-3950
www.viastore.com
