How to optimize Sends in Journeys that use Decision Splits?

When you use DESelect Engage in a Journey that contains Decision Splits, it is expected that the Send preview and the number of contacts entering the Engage component in the Journey do not always match.

DESelect Engage evaluates audiences at the Data Extension level linked to each Send. Journey Builder on the other hand, routes contacts dynamically at the path level (Decision Splits). This means the population in the Data Extension can be larger than the population that actually reaches a specific path in the Journey.

In this article, we will understand why these differences happen and how we can optimize our Sends.
 

Why do the preview and Journey numbers differ?

A common scenario: Multiple Sends use the selected Data Extension as the entry source. After the entry source, a Decision Split divides the audience into several branches (based on a static attribute like a code or preferred channel, or on behavior such as opens/clicks).

When a journey is imported in the List View using the Imported Journey feature:

1. DESelect Engage uses the Data Extension in the entry source (in our example, it contains 254 contacts) linked to the Send via the Engage component. Send 1 and Send 2 will have the same target audience (254 contacts). 

2. Due to the split decision placed after the entry source, the audience is split based on the conditions set (e.g., 54 contacts in the first branch and 200 contacts in the second branch).

3. Engage components evaluate the saturation level of the contact base according to the defined rules and priorities and either include or exclude contacts (e.g., based on the Engage rule, 10 contacts in the first branch may be included, while 44 contacts should be excluded).

Note: Assuming those 10 contacts are undersaturated and the 44 contacts are saturated based on the rules and priorities, the DESelect Engage calendar will still show that most contacts for this Send are saturated. Instead of Send 1 appearing green, it will display red.

4. Send 1 is sent to 10 contacts.

This is expected when Decision Splits, filters, or event-based activities reduce the audience before the Engage step. DESelect Engage relies only on the Data Extension linked to the Send, whereas the Journey relies on path-level routing.
 

How to accurately configure your Sends?

1. Create separate Data Extensions for each Engage component and run those before the journey starts.
    a. Identify the entry Data Extension for your Journey.
   

     b. Determine the Decision Split criteria (i.e contacts split by PreferredLanguage = English vs. Dutch).
   

     c. Create two separate Data Extensions, using the source Data Extension and segmenting your audience based on the Decision Split criteria (preferred language English/ Dutch).
   Recommendation: Feel free to use DESelect Segment to easily create these Data Extensions.
    

2. Link the created Data Extensions for the corresponding Engage component.
   In DESelect Engage, you can either:
    i.Create one Send in the Calendar View per path. Once done, ensure to select the proper Data  Extension recently created for each of the Sends. At the end, you should have 2 Sends in the calendar, with each having the corresponding Data Extensions.

          ii.Import the Journey. Once done, the Sends will automatically get the Data Extension selected as entry source for both Sends. Ensure to replace the Data Extensions with the newly created ones accordingly.