Developing Labour Constants for Building Processes from Work Study in Nigeria

The study was aimed at developing appropriate labour constants suitable for cost estimation of building processes in Nigeria It was a field survey where detailed work study was carried out on two major work sections (concrete work and blockwork) in six building project purposely selected across the South East, Nigeria. Time study was carried out randomly on chosen days (not less than three times) during the entire investigation period in order to obtain different durations and quantity of work completed. Thereafter, the most probable duration time (expected time (t)) to complete each operation that makes up an activity relative to the quantity of work was observed and recorded. From this, the duration time (t_ka), of key process was determined and subsequently, the standard time (S_t) and standard output (S_op) (labour constants) were determined. This study has undoubtedly achieved the development of labour constants which could be used to build up rates for labour by estimators during tendering for projects. It has given an insight into the output level of building operations in the study area which could serve as a base for a reliable and realizable construction programme, accurate cost estimate and reduced suboptimal job performance. It therefore recommended that the practical application of these labour constants on life building projects and an extension of such detailed analytical study in other parts of Nigeria.