Because the number of ships is likely to continue to decline, flexibility surely will be vital. Typically, ships need special computers to assemble the transmitted data into a usable whole. The intelligence itself can be so vital that the need for it may be an important factor in holding the old Cold War alliances together, as navies suddenly deprived of this information may find themselves very nearly crippled. The change may seem invisible. For example, the Chilean Navy is completing a major modernization programme, but the only visible element is a few installations of the Israeli Barak anti-missile missile.
Ships last a long time.
Upgrades and mission changes have been costly, partly because of the need to rewire and to rewrite CDS software. The future is probably exemplified by the US NSSN, which is designed around a new high-capacity databus, chosen specifically to accommodate future sensors, weapons and computers. Fleets must often coordinate with other services. For example, to support amphibious assaults well beyond ships' horizons, the navy needs not only new long-range bombardment weapons, but also a usable dynamic picture of forces ashore. Long-range fire also requires a new generation of IFF systems.