Construction Benchmarking

I want to share with you all my concern regarding how to measure a construction project progress. In planning books they always refer to cost as the benchmak. My view is that cost alone is not the right image of a project progress because, as an example block works is cheap while it takes long time, while setting out a A/C chiller on its base is costly while it take only few days. So my view is that the progress of a construction project should be a compination of three elements, cost, duration, and it is importance weight in the project.

Can you please share me with your practical experience nad ideas.

Thanks