The U.S. Navy has noted a decline in the readiness (for operations, and combat) of its ships over the past decade, and finally conducted an intense inspection of the situation. What was found were several trends, all of them bad, that resulted in it being much more difficult, and often impossible, to maintain ships as they had been in the past. The biggest problem was leadership at the top, which allowed this to happen. The leadership angle was not mentioned in any of the recent studies, but it is at the heart of all the other problems.
Getting down into the details, the most obvious problem is that the ships are getting older, and so is their equipment, especially the electronics. As stuff gets older, it becomes more difficult to get spare parts, or to get them on a timely basis. This is particularly true with Cold War era electronics, which have since been replaced, in the commercial market, by several generations of new (cheaper and more efficient and reliable) gear. The navy chose to try and maintain the older systems. It has not been working at the ship level. Worse yet, the procurement bureaucracy has not kept up with the times (it's a real hassle to order anything), and sailors often give up on trying to get spares, especially when their officers can't make the system work either. All this was made still worse by navy attempts to "streamline" things resulted in smaller spare parts budgets for ships (sometimes based on false belief in a faster spares delivery system that did not exist). Another streamlining disaster was a push for "minimum manning" (only having as many sailors on board as you actually needed). The analysis done to find the optimal crew levels ignored (or simply missed) a lot of manpower intensive jobs that led to many more ships failing their readiness inspections.
The senior admirals now have all this staring them in the face. The question is, can they fix what their predecessors screwed up? The fixes are expensive, and there is still a lot of pressure in the navy to spend lots of money to replace aging ships. To fix the current readiness problems means you will not be able to afford some new ships. The fix is replacing older equipment in current ships, with new, more reliable and easier to maintain systems. Most of the problems are on surface ships (the "surface combatants" like frigates, destroyers and cruisers). Most admirals see the carriers and nuclear ships as the key naval vessels. Should money be shifted from subs and carriers to fix the surface combatants, and similar problems aboard carriers and subs? The navy budget is shrinking, and the answers to these questions will be pretty obvious over the next few years. There are definitely two factions in the navy on this subject, and keeping score is as simple as counting new ships built, and the number of existing ships failing their readiness inspections.