How we can measure the productivity in construction industry?

How much of works done VS How much of Man-hour ,within definite period

By maintaining/incresing the turnover fixed as at time of project been booked and reducing the upcoming cost. Then by the differences of the aforesaid, our net margin will increase gradually. to reduces the costs there are several means like open tendering of various items, keeping strict watch over time vs targets, getting the best person for the job and etc..