Why a modern twelve-ship class can take two decades

How much lead time does a modern navy need for twelve warships of 7,000 to 9,000 tons?

Roughly sixteen and a half years at an aggressive minimum, and more plausibly twenty to twenty-two years under normal conditions.

Modern warships require roughly a decade of concept development, design, and systems integration before steel is cut. Once production begins, a yard building only two or three ships in overlapping eighteen-month cycles still needs years to deliver twelve hulls. Even an idealized throughput calculation places the total program near sixteen and a half years. Normal yard loading, pauses, and inefficiencies can push the practical timeline toward twenty or twenty-two years.