From SCDigest's On-Target E-Magazine
- Nov. 4, 2014 -
Supply Chain News: Finding the Sortation System that is Right for Your Distribution Center
SCDigest Materials Handling Editor Cliff Holste on Keys to Sortation System Success
SCDigest Editorial Staff
In an Supply Chain Digest classic, editor Dan Gilmore spoke a few years ago with our Material Handling System Editor Cliff Holste on several subject related to sortation systems in distribution. Holste has more than 30 years experience with sortation system design and implementation in many industries.
Gilmore: What are some of the first things a company needs to consider if it decides it might need a sortation system in its DC?
SCDigest Says: |
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| It's rare to hear a sortation system horror story anymore. Standardization of equipment design and decades of industry experience have virtually eliminated trial and error methods. |
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What Do You Say?
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Holste: I think there are a number of issues that need to be considered at the outset. For example:
• Is manual sorting (utilizing a re-circulating conveyor loop) a possibility, or does capacity/operational requirements dedicate automatic sortation? The manual sorting option, of course, is only for low volume operations.
• If automation is required - are the cartons conveyable and do they already contain a unique bar code identifier?
• Do you have the internal resources to develop the plans and specifications and handle the purchasing and project management phase of the project, or will you need to obtain outside assistance?
• When you include the cost of the various sub-systems that are required to feed and takeaway product to and from an automatic sorter, even the most basic entry level system will require an investment approaching $750,000 to a million dollars or more. Obviously, costs can increase from there. Have you developed a project budget, and understand how it is going to be cost justified?
• Determine basic system capacity requirements - what will the sorter need to handle and at what rate?
Other things are important, such as determining an overall rough initial system layout, and beginning to think about changeover plans from the old system to the new one, but these things come after these basic questions are answered.
Gilmore: When you've seen companies struggle to get their sorting projects right, what are main reasons that the system fails to meet expectations?
Holste: In situations where system performance is poor, it's generally due to insufficient overall system planning in the concepting and budgeting phase, which can then lead to overlooking important functions and requirements. For instance, in an automated sorting system, having accurate and timely replenishment of inventory in active pick locations is critical to maintaining sorting system performance and customer service levels. If you don't get that right, which is a process outside of the sortation system itself, sorter system performance will suffer or even be considered a failure.
Another example of poor planning might be in failing to appropriately design in after-sort handling and shipping capacity, which can then lead to excessive system backups and shutdowns.
Gilmore: Some companies worry that a sortation system won't be flexible enough to meet future needs, as conditions change. What are the keys to designing a system that has enough flexibility?
Holste: There are several types of sorters available covering a wide range of incremental capacities. Before selecting a sorter, determine what your current capacity requirements are, then add for growth. The sorter may run initially at a rate well below its maximum design speed and then be increased as throughput demands rise.
A typical sorter, operating single shift with normal preventative maintenance, will last 10 to 15 years, and even then it can be refurbished and/or reused in a new location. You have to be sure that the system layout allows for expansion to the picking system (by increasing the picking locations and/or number of pick modules) and the shipping system (by adding more sort locations). However, special attention needs to be given to the location of the sorter induction area, as this is often the most complex part of the system and its location should be considered permanent.
Understand how changes in products, SKU mix, order profiles, and customer demands for value added services will affect the future system operations. Have a plan or strategy worked out for dealing with them before finalizing the system layout.
(Distribution/Materials Handling Story Continues Below
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Gilmore: I know it varies, but at a high level, what sort of throughput improvements do companies typically achieve when moving to automated sortation?
