Apple Inc. is undergoing a rare shake-up of its executive ranks, aiming to get its artificial intelligence efforts back on track after months of delays and stumbles, according to people familiar with the situation.

In the process, the Siri team was reassigned to this new department and placed under Giannandrea’s authority. By early 2019, the new SVP was shuffling things around to refocus on longer-term research, presumably in hopes that taking the broader view would ultimately help Siri improve.

The accumulated failures and humiliations that have dogged Siri in recent years have finally proved too much for Apple’s senior management, who have decided to oust John Giannandrea from his role as Siri boss.