To bid independently, you need to understand drawings, calculate quantities independently, understand the calculation rules of lists and quotas and be able to apply them in practice, be familiar with the operation of budget software, the prices of commonly used materials, the local specification documents and price documents, and the skills of cost calculation and bidding quotation.
Independent audit requires familiarity with the use of lists and quotas, construction contracts, bidding documents, visas, design changes, local specification documents, price documents, construction common sense, etc.
Independent settlement, general budget, plus familiarity with visas, design changes, bidding documents, construction contracts, local specification documents, price documents, etc. can generally be made independently.
Although there are a lot of contents mentioned above, in general, this major should be done seriously for 1-2 years, longer than 3 years, and can basically be completed independently. As for being refined and not refined, it lies in the usual experience accumulation and learning.