Construction delays and cost overruns continue to receive attention from both academia and the industry. Simultaneously, the client organisation has been consistently cited as a primary party that could significantly improve construction performance. However, limited research has been undertaken to bring together client activities and evaluate their effects on construction delays and cost overruns. Thus, this research aims to define the client activities that substantially affect construction delays and cost overruns. It began with a review of the literature on client procurement activities throughout the procurement lifecycle and knowledge from other industries. Then a questionnaire survey method was adopted to explore how public clients' project engineers and managers have involved in and have managed construction procurement in the past projects. The interrelationship between 75 client activities was investigated through principal component analysis, which resulted in the identification of 14 essential client activity components. Multiple regression analysis revealed that construction delays are substantially affected by six client activity components: collaboration, construction efficiency, accuracy of objectives and requirements, difficulties with project planning and permits, contractor difficulties, and requirement modifications by the client. Likewise, construction cost overruns is greatly associated with eight client activity components, namely design efficiency, collaboration, multiphase involvement of stakeholders, objective and requirement changes, client team development, the availability of a construction workforce, contractor difficulties, and requirement modifications by the client. These activity components can help client organisations to easily recognise those activities that greatly contribute to the improvement of construction performance. Clients can then ensure that these activities receive careful and continued attention from the client team. Simultaneously, recognising the effect of these activities on construction performance allows a precise measurement of the competency level that must be attained by the client team and the reduction of costly training in areas that are not necessary. While the research focuses on Oman, there is the potential for these activities to be adopted for use in other developing countries to aid the enhancement of construction procurement performance.

Construction delays and cost overruns continue to receive attention from both academia and the industry. Simultaneously, the client organisation has been consistently cited as a primary party that could significantly improve construction performance. However, limited research has been undertaken ...