I know the program to build the CSC is a long one, and the actual hulls hitting the water are far away. Is it normal to buy a handful or a major component at a time? It seems to me that leaves us open to purchasing the latest versions of components as the program proceeds, but at the same time can increase costs to purchase and we could end up with different blocks of vessels with different capabilities.
It's not normally advertized but the CSC is actually a batch build by nature of the contract. The Gov't isn't signing a build contract for all 15 ships upfront, they will likely do three (hence the 4 Aegis systems, 3 for the ship + 1 for land-based training/testing). Sometime in the middle of the build they will look at the second batch of ships. It will look like this:
3 ships, 4 ships, 4 ships, 4 ships.
This is fair to both the taxpayer and ISI. The ships will be built over 25 years or so. The batch model primarily allows for more appropriate pricing info based on the relevant economy with no crazy forecasting required. It also provides structure to modify the design and contract for any number of good reasons, like a subcontractor going belly up or tech changes.
This is really the way most of these long-term shipbuilding projects go.
I know other programs where all the mission kit was bought, in advance. It sat on shelves for years before being installed. In some case it went obsolete before being used and/or the OEM went out of business, leaving no parts support.
Doing it this way is much safer from a future proofing strategy.
This is very true from a ship design program. When the various organizations stick their noses into the PMO's to say "Oh that isn't the way we do it now." they are often told, "You should have said something 5 years ago when the requirements were written, or 3 years ago when the design was being developed or 1 year ago when the design was approved. Equipment has been bought, the build has started. Too late now".