Northern Trail Outfitters has a master data extension of 880,000 subscribers they want to randomly...

Automation Studio ' s Random Split Activity is purpose-built for exactly this use case: it takes a source data extension and divides its population into a specified number of evenly-sized, randomly-allocated output data extensions — up to 15 target groups in a single configuration — making it the direct, native tool for splitting 880,000 subscribers into 11 test cells for a messaging strategy experiment. This runs as a discrete, batch-oriented step well suited to a one-time or periodic large-scale segmentation exercise ahead of a send. While Journey Builder (B) does offer a Random Split/Engagement Split concept for path allocation within a running journey, it operates at the individual-contact, in-journey routing level rather than as a bulk pre-send data-partitioning tool for building separate testable data extensions, making it a mismatched tool for this specific batch-preparation requirement. Contact Builder (C) is the data modeling and relationship configuration workspace — it does not contain data-splitting or randomization functionality. Email Studio (D) is the content and list-management workspace for building and sending emails; it likewise has no native random data-extension splitting capability. For any ' divide a data extension into N random groups ' requirement, Automation Studio ' s Random Split Activity is the standard answer. Reference: Automation Studio Random Split Activity.