Go to primary content
Oracle® Retail Science Cloud Services Implementation Guide
Release 19.1.003.2
F40917-01
  Go To Table Of Contents
Contents

Previous
Previous
 
Next
Next
 

10 Assortment Recommender

This chapter provides details about the Assortment Recommender, a batch-run system that provides recommendations for changing the current assortments in each store and each category in order to increase revenue or gross profit from that category at that store.

Prerequisites

The Assortment Recommender relies on output from the DT application of the application. In particular, every category/store combination that is to receive assortment recommendations must have DT results in an approved DT version. Some of the concepts used in the Assortment Recommender, such as substitutable and incremental demand, are concepts that the DT application also uses.

Producing Better Assortments

The Assortment Recommender starts from the current assortments for each category in each store and finds assortment changes that will increase either the total revenue or total gross profit of the assortment. Each category-store combination is optimized separately.

The total revenue or total gross profit calculation accounts for

  • Cannibalization effects, by using demand transference, and

  • Halo effects, meaning additional revenue a SKU in category brings by encouraging the purchase of complementary SKUs in other categories.

The assortment changes recommended are those that improve revenue or gross profit after accounting for the above effects. For example, the Assortment Recommender may recommend dropping an item that is very similar to the other items in the assortment and replacing it with an item that is less similar to the other items, because dropping the similar item does not decrease total revenue by much, and adding the dissimilar item brings in additional revenue. Similarly, the Assortment Recommender may recommend dropping a SKU that brings little halo revenue in favor of a SKU that brings in more halo revenue (or gross profit).

The calculation of revenue or gross profit does not include any revenue that an assortment change in other categories may bring though halo effects. Each category at a store is optimized separately, so when optimizing a category B, it is not possible to include revenue that another category A may bring to B through the halo effect of a SKU in A on B.

The Assortment Recommender lets you choose which of the following to maximize:

  • total assortment sales units

  • total assortment revenue

  • total assortment gross profit

These quantities include halo sales units, halo revenue, or halo gross profit, respectively

The Assortment Recommender runs as a batch process and on a set schedule produces recommended assortment changes for each category/store combination using whatever is the current assortment at the time it runs. See the following sections for how the schedule can be configured.

Run Groups and Run Frequency

It is unnecessary to obtain frequent assortment-change recommendations for every single category/store combination. For many category/store combinations, recommendations may only be necessary at infrequent intervals, or not at all. The Assortment Recommender provides interfaces to allow external control of the run frequency of category/store combinations in the following way.

The interfaces allow for defining a run group, which consists of a set of categories and a set of stores. When a run group executes, every combination of category/store from the set of categories and set of stores receives new recommendations. The run group as a whole is associated with a run frequency, which specifies how often the category/store combinations in it receive new recommendations. In this way, the run group is a mechanism to control:

  • The category/store combinations that receive recommendations. For example, if, for category A, only stores 1, 2, and 3 should receive recommendations, then a run group can be set up with category A, and stores 1, 2, and 3.

  • The frequency of recommendations. A retailer may be particularly interested in certain key categories, so it makes sense to schedule recommendations only for those categories. However, not every category may need frequent recommendations.

Keep in mind that when the run group executes, every combination of category/store in the run group receives recommendations. If the run group has 10 categories and 500 stores, this is 10 x 500 = 5,000 sets of recommendations and 5,000 separate calculations to produce those recommendations.

The Run Group Parameters

Various parameters control how the recommendation calculation proceeds when a run group executes. These parameters must be present in the run-group tables in the database. Within a run group, each category has its own set of these parameters because the parameters depend on the category. The parameters are:

  • The set of Must-Keep SKUs. Each category in a run group can have a list of such SKUs, which indicate to the Assortment Recommender that these SKUs must not ever be removed from the assortment. For example, key items for the retailer in the category must be on the list. The list can be empty, in which case the assortment recommender is free to swap out any SKU currently in the assortment.

  • The Assortment-Size Change. This is an integer that can be negative, positive, or 0. It indicates the change the Assortment Recommender must make to the number of SKUs in the assortment. Suppose the value is C. Then the Assortment Recommender will change the assortment size by C. If C is 0, then the assortment size stays the same. If negative, the assortment size decreases by -C, and if positive the assortment size increases by C. There is one value of C for each category in a run group. For a given category, C applies to all of the stores in the run group. It may not be possible for the Assortment Recommender to achieve a change of C for a particular category in a particular store, but it will attempt to get as close as possible.

  • The Min-Keep Percent. This is a non-negative percentage. Suppose the value is M. Then the Assortment Recommender keeps at least M percent of the SKUs in the assortment to be the same. Suppose M were 50 percent. Then at least half the assortment will consist of SKUs that are already in the assortment, but the Assortment Recommender is free to choose which 50 percent to change. This parameter, along with the Must-Keep SKUs, is useful for ensuring that the Assortment Recommender does not make too many changes to the assortment.

  • The assortment metric to maximize. The choices here are: sales units, revenue, or gross profit. This is a total over the entire assortment, and the Assortment Recommender recommends assortment changes that increase the chosen metric from what it is for the current assortment. The choice of assortment metric is per category within a run group, and it applies to all of the locations in the run group. For example, if a certain category is a loss leader but drives the customer to make other purchases, then the choice of metric for this category might be sales units.

Data Used by the Assortment Recommender

The Assortment Recommender requires the following data to generate assortment recommendations. Each data element is derived automatically from other data in the application schema and fed into the Assortment Recommender. The following list describes the data and how it is derived.

Required Data

  • The current assortment for each category at each store. As discussed above, for each category/store combination in a run group, the Assortment Recommender starts with the current assortment and makes changes to it to increase the chosen assortment metric. For each category/store combination, the system takes the SKUs that were selling in the store during the last available week of historical data.

    The weekly sales-units rate of each SKU in the current assortment. This is calculated through an average over the most recent four weeks of historical data.

  • The price of each SKU in the current assortment. Historical price data is not used for this, but instead the total revenue over the most recent four weeks of historical data is divided by the total sales units over the same four weeks. This provides an average historical price, based on the last four weeks of historical data.

  • The gross profit of each SKU in the current assortment. Historical price or cost data is not used; instead, an average is taken similarly to the price calculation. The total gross profit is taken over the most recent four weeks of historical data and divided by the total sales units over the same four weeks.

The sales-units rate, price, and gross profit are required in order to support the possible assortment metrics.

Notice that in addition to data about the current assortment, the Assortment Recommender requires data about possible SKUs that it can swap into the assortment, since otherwise, in the case of keeping the assortment sizes the same or expanding the assortment, no recommendations would be possible. (The case of decreasing assortment sizes is discussed separately below.) For each category/store combination in a run group, the system calculates the following for the possible SKUs to be swapped into an assortment:

SKU Data

  • For a category/store combination, the set of new SKUs is the SKUs that are in the current assortments of other stores but not in the current assortment of this store. (See above for how the current assortment of a store is determined.)

  • The price of the new SKU is the average of the prices in the stores in which it is part of the current assortment. The price at each store in which it is selling is determined as described in "Required Data".

  • The gross profit of the new SKU is the average of the gross profits in the stores i which it is part of the current assortment. The gross profit at each store in which it is selling is determined as described in "Required Data".

  • Assigning the sales units rate of the new SKU is the trickiest to handle, since the sales-units rate of the new SKU must be forecast based on the assumption that it is selling at a store where it may not have sold before. Here, the Assortment Recommender identifies like items of the new SKU among SKUs that are currently in the assortment at the store, and from the like items it makes a forecast of the new SKU's sales-units rate at this store. Identifying the like items is done through the use of similarities. For more information about similarities, see the section "The Role of Attributes in Calculating Similarities".

If the Assortment-Size Change parameter is set to a negative value, then it is possible to decrease the size of the assortment without having data about possible SKUs to swap into the assortment, as in this situation the Assortment Recommender would simply be finding SKUs to delete from the assortment while still maximizing the chosen assortment metric.

Halo Effects

As mentioned above, the Assortment Recommender accounts for halo effects when calculating the selected assortment metric. This calculation uses the output of the Affinity Analysis. AA determines halo effects at the sub-class level. That is, sub-class A of one category has a halo effect on sub-class B of another category, meaning some significant fraction of the people who purchase in a SKU in A also purchase a SKU in B. Suppose the Assortment Recommender is running for a particular category C. The Assortment Recommender, when it considers putting a SKU C into the assortment, adjusts upward the amount of the assortment metric that C brings in order to include the halo effect. For example, suppose C is a SKU in sub-class A, and sub-class A brings a halo lift of 10 percent to sub-class B. If the metric the Assortment Recommender is maximizing is sales units, then to the sales units U of C itself, the Assortment Recommender adds sales units of 0.1U to represent the sales units of B bought by purchasers of C. Similarly, if the chosen metric is revenue, then to the revenue brought by C itself, 0.1U times the average price of SKUs in sub-class B is added. The average price of SKUs in sub-class B is calculated by a weighted average of prices, with the weights being the weekly sales-units rates.

The handling of gross profit is similar to the handling of revenue, except that a weighted average of gross profits of B is used instead of the weighted average of prices.

The above discussion involves adding SKU C to the assortment, but the same discussion holds if the Assortment Recommender is removing SKU C from the assortment.

Troubleshooting

Several conditions can prevent the Assortment Recommender from producing recommendations for specific category/store combinations. When any of these occur, the Assortment Recommender will not produce an error but will simply not produce recommendations for the particular category/store combination.

  • The DT application was not run for a particular category, or the category does not have an approved DT version associated with it. This means the category does not have results from the DT application, and without those results, it is not possible for the assortment recommender to run since it cannot account for demand-transference effects. In this case, the category will not receive any assortment recommendations regardless of store.

  • The Assortment Recommender was not able to find any new SKUs for the particular category/store combination. In the above description about finding the set of new SKUs, it is possible that the procedure does not find any new SKUs at all, perhaps because all of the stores are assorted identically at that point in time for this particular category. This may happen with categories that are less important to the retailer, so that the retailer does not see any benefit in tailoring the assortment within each store.

  • The Assortment Recommender was not able to find any assortment changes that result in an increased assortment metric. This can happen if:

    • There were no new SKUs available (see previous item).

    • The number of new SKUs available was very small.

    • The run-group parameters for the category are too restrictive. For example, too many SKUs are listed as must-keep SKUs or the min-keep percentage was set too high (greater than 80 percent).

  • The Assortment Recommender may run, but without using halo effects if the halo effects are not available. For example, the AA may not have run or may not have produced halo effects for the category in question.