###### Abstract  
Construction projects are planned in a complex and dynamic environment characterized by high risks and uncertainties amidst resource constraints. Assessing construction schedule risk facilitates informed decision-making, especially in a resource-constrained situation, and allows proactive actions to be taken so that project objectives are not jeopardized. This study presents a stochastic multiskilled resource scheduling (SMSRS) model for resource-constrained project scheduling problems (RCPSPSP) considering the impact of risk and uncertainty on activity durations. The SMSRS model was developed by integrating a schedule risk analysis (SRA) model (developed in MS Excel) with an existing multiskilled resource scheduling (MSRS) algorithm for the development of a feasible and realistic schedule. The computational experiment carried out on three case projects using the proposed SMSRS model revealed an average percentage deviation of 10.50%, indicating the inherent risk and uncertainty in activity durations of the project schedule. The core contribution of the proposed SMSRS model is that it: (1) presents project practitioners with a simple tool for assessing the risks and uncertainty associated with resource-constrained project schedules so that necessary response actions can be taken to ensure project success; (2) provides the small-scale construction businesses with an affordable tool for evaluating schedule risk and developing a feasible and realistic project schedule. s 2021 11 650 10 December 2020 8 January 20  
developing a schedule with realistic project durations [6] especially when dealing with a resource-constrained project. This is because the CPM schedule is based on optimistic activity durations and the assumption that resources are unlimitedly available which is unusual in a real project scenario [6; 7; 8]. Every construction project is prone to risk [8], uncertainty, and constrained with resources [9]. Thus, risk and uncertainty related to the project schedule must be assessed to enhance project success while ensuring the development of a time-resource-feasible schedule considering the resource constraints. Further, schedule risk analysis (SRA) and multiskilled resource scheduling (MSRS) are the strategies used to address schedule risk and resource constraints. On one hand, SRA involves linking the risk information of each activity of a project to the schedule baseline, in order to understand sensitivity information of each activity and to access the effect of uncertainty on the final project duration and cost [10]. On the other hand, MSRS is an extension of resource-constrained project scheduling problems (RCPSP) used as an optimization approach used for tackling the inefficiency of the single-skilled resource (SSR) scheduling strategy and to reduce project delay while utilizing scarce resources effectively to achieve project success. Although, various tools, models, and methods used for carrying out SRA and MSRS have been developed and adopted by practitioners and researchers. For example, @Risk (at-risk) is a Monte Carlo simulation-based commercial software and an add-in to Microsoft Excel developed by Palisade used for cost and schedule risk analysis. However, the software focuses on determining realistic activity durations without considering resource constraints. Moreover, the cost of purchasing the software and training is too high to be affordable for small-scale firms, especially in developing countries. Additionally, among the numerous MSRS models that have been proposed in the literature, the heuristic algorithm for MSRS proposed by [11] remains the most applicable method for the scheduling of construction projects under resource-constrained due to its simplicity and explicit scheduling procedures. However, the schedule generated using the algorithm is based on a single point (deterministic) activity durations with no consideration for risk and uncertainty inherent in activity durations. Managing projects with such a schedule can lead to project slips.