Factors affecting construction-planning outcomes

Research on uncertainty in construction has emphasized the importance of incorporating uncertainty factors in project-cost and time forecasts. However, little attention has been paid to identification and quantification of the specific risks. The present paper focuses on an assessment of the effect of uncertainty on the outcomes of planning. The effect of eight situational variables is evaluated by measuring the schedule and man-hour variances of the project, as well as the extent of usage of plans. The variables examined are number of subcontractors, number of trades, objectives rigidity, percentage completion of design, past construction experience, predictability of weather, availability of labor, and attitudes toward planning. The findings show which of the various situations affect any one planning measure, as well the extent of such influence. The paper concludes with an analysis of the financial implications of the prevailing practice of overlapping design and construction.