Sorting Out Your Sortation Options: Guiding You Through the Process of Evaluating and Selecting the Right “Mission-critical” Sortation Solution

Tim Kraus, Director, Product Management, Honeywell Intelligrated; and Satyen Pathak, Global Product Manager, Honeywell Intelligrated

Whether from growth, consolidation of facilities, mainstreaming of processes, business acquisitions or simply a need to become more efficient, there are several reasons to consider automated sortation solutions. Even if you have a specific solution envisioned, it is beneficial to evaluate several significant factors to be considered when choosing the “mission-critical” solution for your sortation system.

The purpose of this white paper is to guide you through the process of evaluating and selecting the right sortation solution for your facility. Several widely accepted sortation technologies will be examined on a number of aspects that you should consider before deciding on the right fit for your needs. This paper will walk through all of the important factors to consider as you “sort out your options” and ensure that you are making the right decisions for your facility’s needs today and in the future.

Sorting Out Your Application

Most sorters can be grouped into one of two high-level classifications: line or loop sorters. Line sorters are configured in a straight line, with items entering the sorter at only one location. They typically need separate conveyors for items that cannot be successfully sorted on the first pass. By contrast, loop sorters are configured in a continuous circle, often with more than one induction point in which items are introduced to the sorter. They also have built-in recirculation, which can help provide more confident, reliable divert confirmation signals from the control system.

Sorting Out Your Handling Requirements

One set of factors that have a significant influence on MHE technology selection are the physical features of the items to be sorted, including the types of items and their packaging. Items, for the purpose of this paper, are the individual products, units, cartons or totes that will be sorted. Not all sortation technology is ideal for all types of items.

Overall, there are several factors to consider, including:

1. Types of items to be sorted (corrugated carton, tote, polybags, bubble mailers, loose items, etc.)
2. Item packaging type (corrugate, shrink wrap case, bagged apparel, apparel on hangers, etc.)
3. Item diversity (50% corrugated carton, 25% bagged apparel, etc.)
4. Item structural integrity (the rigid and predictable the structure of the items)

Keeping in mind that most applications do not handle a single item type, it is important to recognize that a system must accommodate a wide range of item types. The more item types the system can handle, the fewer non-conveyables there will be—increasing facility efficiency and shortening the payback of the investment. Take into account your entire product mix for present and future needs when making your selection.

Aspects such as size, weight, balance or the shape of the product to be sorted may rule out certain sortation technologies. Packaging integrity of the items, such as “perfect presentation” needs and durability concerns, (due to reproduced packaging) must also be considered.

Note: for complete definitions of the technologies mentioned in this paper, please see the Glossary at the end of this paper.

Sorting Out Your Rate

Another critical factor to consider is the rate requirement of the system. For the purpose of this paper, “rate” relates to the item throughput per hour or the rate at which the system must operate. In the material handling industry, this is also expressed in terms of cartons per hour (cph) or pieces per hour (pph).

A common misunderstanding about rates is that “speed” (or how fast the equipment runs) is the same as throughput. However, concentration on speed alone can steer your selection in the wrong direction. Speed, without consideration of other factors, such as gapping, gentle handling and accuracy, can actually be an inefficient use of the technology.

Instead, as systems have been pushed to continually increase rates, MHE vendors have worked to increase throughput without increasing machine speed. This reduces wear, energy usage and noise, while extending equipment life. It also makes the machine control system much more critical on sliding shoe and pop-up wheel sorting technologies. An increased rate at reduced speeds requires reducing gaps between items while maintaining divert accuracy.

In sortation equipment, as rate and handling capability increase, so does the cost of the technology. System implementation payback must be carefully balanced with rate to meet an acceptable budget for any project.

Some rate requirements may immediately rule out certain sortation technologies. (Actual rates are highly dependent on a number of factors, but the chart titled “Throughput Rate” will help in learning the most common rates by technology.)

Sorting Out Other Considerations

In addition to handling, rate and application requirements, other factors can make a big impact on the technology decision.

Floor space requirements – Many facilities are looking to add e-commerce-focused solutions in existing buildings, sometimes even in the back room of retail stores. Some technologies are designed to maximize the number of destinations in a very small footprint.

Operating noise levels – Some sortation equipment operates at very low noise levels while maintaining very high rates, increasing ergonomic comfort, while still maintaining throughput.

Investment level – While some sortation systems require more substantial technologies and supporting subsystems, they can better prepare the operation for future growth.

Energy usage – Energy usage is becoming an increasingly important aspect of the material handling system. If energy usage is an important factor in your enterprise, be sure to share this concern with your MHE vendor at the project outset, as energy usage can vary widely by technology and vendor.

Maintenance and operator skill levels – Both the daily operation and maintenance tasks can vary widely by technology and by MHE vendor. Consider how your personnel will interact with the equipment and how your current staff will be able to maintain the system.

Future expansion – If there is a possibility for future expansion, this should be taken under consideration at the project outset. The ability of future expansion, in terms of rate or divert locations, can be limited by the technology or by the initial system design.

Divert accuracy – Divert accuracy and propensity for jams, hang-ups and mechanical problems can often be dependent on the specific design details by the MHE vendor and the gapping requirements designed for the system.

Divert confirmation – Confirming a divert can be a necessary step in some sortation processes. The method for confirming a divert varies by the sortation technology and the machine control software used by the MHE vendor.

Depreciation schedule – Some sortation technologies may have a longer expected life span, which will affect the depreciation schedule. This must be clearly understood before making the purchase, so project costs are properly distributed.

Summary

This paper has discussed critical factors to evaluate during a typical automated sortation investigation—but there are also several details which can only be learned through experience. Before construction plans begin, be sure to talk to an MHE vendor with significant, unbiased experience in a wide variety of sortation technologies. This will ensure the best possible, cost-effective solution is developed prior to submitting a budget for capital approval. WMHS