PurposeConstruction labour productivity is of great interest to practitioners and researchers because it affects project cost and time overrun. This paper evaluates and ranks the importance, frequency and severity of project delay factors that affect the construction labour productivity for Malaysian residential projects.Design/methodology/approachA total of 100 respondents consisting of 70 contractors, 11 developers and 19 consultants participated in this study. The respondents were asked to indicate how important each item of a list of 50 project related factors was to construction labour productivity. The data were then subjected to the calculation of importat indices which enabled the factors to be ranked.FindingsThe five most important factors identified by them were: material shortage at site; non‐payment to suppliers causing the stoppage of material delivery to site; change order by consultants; late issuance of construction drawing by consultants; and incapability of contractors' site management to organise site activities. On the other hand, the five most frequent factors were: material shortage at project site; non‐payment to suppliers causing the stoppage of material delivery to site; late issuance of progress payment by the client to main contractor; lack of foreign and local workers in the market; and coordination problem between the main contractor and subcontractor.Originality/valueThe inferences drawn from this study could be used by the project managers to take account of these factors at an early stage, hence minimising the time and cost overrun.

Purpose -Labour usage represents one of the critical elements in the Malaysia construction industry due to severe shortage of local workers. This paper aims to present a construction performance comparison between conventional building systems and industrialised building systems (IBS). Design/methodology/approach -Data were obtained from 100 residential projects through a questionnaire survey in 2005. A total of 100 respondents participated in this study. Findings -Analysis of variance (ANOVA) results indicated that the actual labour productivity comparison between conventional building system and IBS was significantly different. Further, the comparison of crew size indicated that the conventional building system of 22 workers was significantly different from the IBS of 18 workers. Similarly, the cycle time of 17 days per house for conventional building system was found to be significantly different from the IBS of four days. However, the conventional building system was found to be insignificantly different from the IBS in term of structural construction cost. Originality/value -The results acquired from this study could be used by project planners for estimating labour input, control costs and project scheduling. Additionally, they could be used to determine the most appropriate structural building system for executing a construction project at the conceptual stage.