Analytical Estimating
Analytical estimating is a work measurement technique. A task is broken down into basic component operations or elements. If standard times are available from another source, these are applied to elements. Where no such times are available, they are estimated based on experience of the work. The estimating is done by a skilled and experienced worker who has had training in the process of estimating and who simply estimates the time that would be required by a fully competent and experienced worker, working at a defined level of performance.
The analysis into elements is a key factor in producing reliable times. While time estimates for individual elements may be inaccurate, any errors are random and one will compensate for another. Also, as the technique is normally used for assessing workloads over a reasonably long planning period, errors in individual tasks also cancel each other out.