(Bloomberg) -- 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.Most Read from BloombergNew York Subway Ditches MetroCard After 32 Years for Tap-And-GoDespite Cost-Cutting Moves, Trump Plans to Remake DC in His StyleAmtrak CEO Departs Amid Threats of a Transit Funding PullbackLA Faces $1 Billion Budget Hole, Warns of Thousands of Lay