For at least the last two decades, one of the Material Handling Industries most challenging objectives has been providing a practical solution for sequencing products to optimize building customer specific mixed SKU unit loads. The challenge becomes even more difficult when trying to satisfy customer’s that need mixed SKU loads that are also optimized by aisle and product location within the aisle. However, given the broad range of equipment and handling technology that is now available, the industry seems to be rapidly developing practical solutions that solve this problem in a variety of cost effective ways.

A Quick Walk Down Memory Lane

When I think about the benefits of product sequencing it takes me back to the first job I had working after school in a grocery supermarket. Way back then supermarkets were much smaller than they are today, although large when compared to the typical neighborhood Mom & Pop store. They were open from 9 till 6 every day except Thursday and Friday when they were open 9 till 9. They were closed on Sunday – as was the law in most communities across the US at that time.

While I was trained to do a variety of tasks including running a checkout cash register (way before bar code scanners) and bagging customer’s groceries, my primary responsibility was keeping the grocery aisles stocked with product, and of course, working with customers who needed help finding what they were looking for.

Every day we had to “face” the shelves (moving oldest product to the front), and report to the store manager what items were below the minimum on-hand quantity (no POS re-ordering system).

There was no VAS (Value Added Services) performed at the DC. Grocery DCs were more like warehouses then - not yet capable of picking individual items or split case quantities. So, the manager could only order replenishment in full case quantity. In those days every item sold in the store had to be stamped or ticked to indicate the selling price. Therefore, pricing was done at the store during stocking.

Typical of most retail stores of that period - there was very little back room space. To make matters worse, glass beer and pop bottles, which were returned to the store for refund, consumed much of the available storage space. So the trick was to order a sufficient amount of each item for the following week without overflowing the shelf space allocated to an item. However, some overflow was unavoidable and we had to find space for those items either over top of the shelves or on the floor under the bottom shelf – not an ideal arrangement.

At 7:00 AM every Saturday morning we started unloading the dry goods trailer that had arrived over night. We received one trailer per week. Meat, produce, and frozen items arrived 2 to 3 times a week on small refrigerated vans.

At the DC, cases were floor stacked in the trailer in a random sequence (no family grouping). Pallet loads of product (usually sale or promotional items) would be stretched wrapped and sitting on the tail end of the trailer. We had to get those off first using a pallet jack. Fortunately, the store was equipped with a dock. Not all stores had one. Thankfully, this didn’t happen very often, but when it did it was a big handling problem for us. We had no space to stage a pallet load in the backroom, and putting a pallet load anywhere on the sales floor was not allowed. There was no end of aisle sales space for promotional items like there is today. So a display would have to be built somewhere in the store – all of which took a lot of time to arrange and setup.

Unloading a full trailer usually took a few days. Working in the confined space of the backroom, we would unload and stack cases onto small narrow hand carts, sorted by product sequence within the aisle. Most often we would double and triple handle cases while trying to sort and arrange them on the carts. We had to unload and restock in phases in order to avoid gridlock in the backroom. All items had to be reconciled against the manager’s order and any discrepancies noted.

Store aisles were much narrower than they are in today’s big box supermarkets. So, in order to minimize aisle congestion and related safety issues, we were allowed to restock during slow periods only. During holidays and peak seasons we were forced to restock at nights after the store was closed to customers.

Pick At The DC To Optimize Putaway At The Store

Why this walk down memory lane? Because years later, working in the material handling industry and being responsible for system development and design, my practical experience working in the supermarket came into play. I knew there would be significant labor benefits picking, sorting, and loading products at the DC in a certain order to expedite handling and putaway once they reached their store locations. Also, I could understand how doing certain VAS operations, like kitting, building displays, price ticketing and/or seeding, at the DC was more practical and cost effective than doing this work in the restricted confines of each individual store.

The concept of product sequencing actually has its roots in the auto industry where they perfected sequencing of parts for their assembly operations. They order specific items from their suppliers and expect that they will be delivered just-in-time and in the same sequence as they will be needed on the assembly line.

In addition to reducing restocking time once product arrives at the store, it also lessens backroom congestion and promotes safe handling practices reducing injury and product damage. For these reasons, and many others, large retail operations, especially in grocery and beverage, are deploying automated material handling system technologies that are capable of product sequencing.

The Future for Product Sequencing

Typically, batch order picking and sorting systems, especially those that are capable of producing an optimized store ready and aisle specific unit load, involve lots of buffer accumulation conveyor footage, high speed merging, induction, and sortation systems, along with sophisticated software and system controls. All this additional equipment and technology increases the system’s overhead cost and making it difficult for some companies to justify. This is the primary reason why only selected large operations have been able to take advantage of automated product sequencing systems.

However, that may be about to change with the adoption of automated discrete order picking methods, which we first reported on last year (see – Automated Case Picking 2009). Within this report there are several different types of ACP systems described.

Because ACP methods eliminate picking labor - discrete order picking is just as efficient and productive as batch order picking. In some applications, the automatic picking of discrete orders will reduce overall system cost by eliminating the order consolidation sorter and much of the associated accumulation conveyor.

As it relates to product sequencing and the building of store ready, aisle specific unit loads, the “Case Sequencing System”, as described on page 27 of the SCDigest report, is a good example of how this evolving technology will serve to simplify, and thus make affordable product sequencing systems for a broad range of companies.

Final Thoughts

While this is good news for those companies who will directly benefit from this higher level of customization, it will also improve Supply Chain speed and productivity which will in turn benefit all of us.

Agree or disagree with Holste's perspective? What would you add? Let us know your thoughts for publication in the SCDigest newsletter Feedback section, and on the website. Upon request, comments will be posted with the respondent's name or company withheld.

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