Classification of work based on their cost: ● Major work : The work which costs more than 2 lakhs is called as major work and estimation of such major work is known as major estimation. ● Minor work : The work which costs more than 50,000 but less than 2 lakhs is called as minor work and estimation of such minor work is known as minor estimation. ● Petty work : The work which costs less than 50,000 is called as petty work and estimation of such petty work is known as petty estimation