The U.S. Navy is becoming more enthusiastic about adopting the automation that enables shipping companies to run huge ships, with crews of less than 20-30 sailors. While the navy needs more sailors to operate the weapons, and larger number of sensors (anti-aircraft and anti-submarine), these can benefit from automation as well.
This "smart ship" type automation enables crew size to be greatly reduced. The "smart ship" gear also provides better networking (communication between people and machines) and power distribution. In effect, the "smart ships" are wired quite differently than current ones. Hundreds of sensors monitor ship systems, not just to see if they are working, but to detect if they are showing signs of failing. This is a big help, since systems can be fixed methodically and under less stressful conditions, rather than in a rush, when one fails unexpectedly, often when greatly needed.
The commercial sensor systems also generate parts orders and keep track of those parts and the status of needed repairs and maintenance. Sensors can also monitor voids (spaces that are never entered by the crew) and the hull. Commercial shipping firms comprise a huge market for these sensor systems, and this spurs constant research and development efforts. The navy thus saves lots of money by not having to develop this stuff themselves. When sensors have to be modified for warship use, the manufacturers are usually willing to do the development for that, if there's a large enough order on the table.
All this can reduce the crew size by 20-30 percent (current destroyers have a crew of 320, with the cruisers carrying 350) if existing ships simply get a lot of these sensors during one of their periodic refurbishments. Newly built ships, like the American LCS type frigate has a crew of 120, compared to the previous Perry class frigates, which needed 176 sailors. Thus, just with existing smart ship tech, warship crews can be cut by a third. Since development in this field continues, crew size will continue to shrink.
In addition to considerable cost savings (over $100,000 a year per sailor), a smaller crew takes up less space, enabling the smaller crew to have more comfortable living quarters. This is a big deal as far as morale and retention (getting people to stay in the navy) goes.
The smart ship approach also influences ship design. Commercial ships are designed to be as inexpensive as possible, while still getting the job done. Warships tend to be built with tradition (what worked before being preferred to new ideas). If smart ship attitudes were used in warship design, the ships would be cheaper to build, and operate more effectively and efficiently.