Building site by Otago Polytechnic

On time and on budget

Nilmini Thilakarathna wants to reduce waste in the construction industry.

The construction industry is notorious for cost and time over-runs. The unexpected delays and extra costs are frustrating for developers and other clients, and are largely attributable to non-value-adding activities in the process of construction. Minimising the activities which don't add value to the project would also improve project profitability for construction companies.

Nilmini Thilakarathna, a lecturer in our College of Engineering, Construction and Living Sciences, has investigated the problem in the Sri Lankan construction industry, and the results are relevant for New Zealand as well. Focussing on flow activities, she has identified seven categories of waste, including over-processing, waiting time, double-handling of stock on site, unnecessary transportation when local suppliers are not used, and defects requiring rework.

Nilmini has also identified 20 lean construction techniques to minimise waste, 19 of which are already being used in Sri Lanka to some extent but not consistently across all construction companies or all projects. There are opportunities to significantly reduce non-value-adding activities in New Zealand. Developing a waste reduction culture in the construction industry would increase the likelihood of projects being completed on time and on budget.