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Purpose – Developing an optimized project schedule that considers all decision criteria represents a challenge for project managers. The purpose of this paper is to provide a multi-objectives overall optimization model for project scheduling considering time, cost, resources, and cash flow. This development aims to overcome the limitations of optimizing each objective at once resulting of non-overall optimized schedule. Design/methodology/approach – In this paper, a multi-objectives overall optimization model for project scheduling is developed using particle swarm optimization with a new evolutionary strategy based on the compromise solution of the Pareto-front. This model optimizes the most important decisions that affect a given project including: time, cost, resources, and cash flow. The study assumes each activity has different execution methods accompanied by different time, cost, cost distribution pattern, and multiple resource utilization schemes. Findings – Applying the developed model to schedule a real-life case study project proves that the proposed model is valid in modeling real-life construction projects and gives important results for schedulers and project managers. The proposed model is expected to help construction managers and decision makers in successfully completing the project on time and reduced budget by utilizing the available information and resources. Originality/value – The paper presented a novel model that has four main characteristics: it produces an optimized schedule considering time, cost, resources, and cash flow simultaneously; it incorporates a powerful particle swarm optimization technique to search for the optimum schedule; it applies multi-objectives optimization rather than single-objective and it uses a unique Pareto-compromise solution to drive the fitness calculations of the evolutionary process.

The present study is an attempt to address the efficiency and performance of construction companies in Egypt. This study highlights and compares different types of organizational structures of contracting firms of classification "A". Comparison covers Functional, Divisional and Matrix organizational structures. It analyses and evaluates the effect of the organizational structure on the contracting companies' performance and success. Restrictions of contracting firms of classification "A" according to EFCBC (Egyptian Federation for Construction and Building Contractors) on companies' performance are investigated. Seven main contracting firms of classification "A" representing private, business and public sectors are considered in the present field survey. The field study is conducted by using survey questionnaire, personal interviews for the companies' employees and formal data from the selected companies. Obtained results show that the organizational structure operates in its highest efficiency when hiring minimum number of most qualified personnel. Moreover, avoiding centralization i.e. routine; bureaucracy and long paper work have a significant impact. This research confirmed the domination of functional organization structure in Egyptian companies. The study concludes that a composite structure between matrix and functional organizational structure based on (geographical location or project type), may be recommended as the optimal organizational structure for contracting firms of class "A" in Egypt.

Duration, cost, and resources are defined as constraints in projects. Consequently, Construction manager needs to balance between theses constraints to ensure that project objectives are met. Choosing the best alternative of each activity is one of the most significant problems in construction management to minimize project duration, project cost and also satisfies resources constraints as well as smoothing resources. Advanced computer technologies could empower construction engineers and project managers to make right, fast and applicable decisions based on accurate data that can be studied, optimized, and quantified with great accuracy. This article strives to find the recent improvements of resource-scheduling problems and time-cost trade off and the interacting between them which can be used in innovating new approaches in construction management. To achieve this goal, a state-of-the-art review, is conducted as a literature sample including articles implying three areas of research; time-cost trade off, constrained resources and unconstrained resources. A content analysis is made to clarify contributions and gaps of knowledge to help suggesting and specifying opportunities for future research.