## 1 Introduction  
Time uncertainty is ubiquitous in all disciplines of project planning and scheduling, yet in the construction industry it is of particular importance [1, 2, 3, 4, 5, 6]. In particular, the uncertainty and risk associated with scheduling is an important aspect of large and complex construction projects [7, 8, 9, 10]. In fact, successful project completion is mainly the result of a variety of multidirectional and comprehensive activities in the area of the creation of companies' intellectual capital, preparation of flexible plans and schedules, and their posterior implementation [3]. The analysis of completion times for individual activity tasks as well as entire phases/stages of the construction process should help project managers understand the factors that influence the final estimate of project duration [1, 10]. Among the methods used for project scheduling, the best known (and most commonly used) are the critical path method (CPM) [11, 12] and the programme evaluation and review technique (PERT) [10]. These methods are based on the determination of minimum times assigned to individual tasks/activities of the project, without which its realisation is not possible. More precisely, these tasks are critical activities that have a direct impact on the overall duration of the project completion. In other words, any change in the duration of the critical activities affects the project deadline. However, schedules developed with the use of these classical deterministic methods represent completely unrealistic expected project deadlines that are very likely to be exceeded [8]. Methods like CPM and PERT were criticised by a number of researchers for being not true models of the construction process. These methods lack the adequacy to model complex logic and resource constraints in a construction process [13; 14; 15; 16; 17; 18; 19]. This form of scheduling seems to be particularly unsatisfactory for construction projects, where exceeding completion dates carries heavy penalties [9]. In any project there is also a whole range of activities whose possible disruption does not always affect the project's target completion date (in this sense they are non-critical activities); in such cases there are some flows or slacks, providing a certain degree of execution flexibility in terms of time buffers. In other words, a float, or slack is the amount of time by which a project or activity can be delayed without extending the completion time of the entire project; while the total slack is the amount of time by which the entire project can be delayed without postponing the ending date of the project. To some extent the shortcomings of the deterministic methods can be solved with the Critical Chain Project Management (CCPM) method, which addresses resource alignment (and resource constraints), requiring some flexibility in resource allocation and individual stages' starting dates [20]. In other words, an appropriate use of resources plays a key role in the CCPM method. The results confirm that CCPM can perform better than the traditional CPM method, which translates into significantly shorter construction times combined with accurate resource levelling at the early stages [20]. The application of CCPM leads to a reduction in indirect costs due to shorter project implementation times and a reduction in direct costs as a result of better allocation of resources and ensuring their timely availability. Also, many problems related to project implementation and project management can be solved with the use of game theory, which allows for the shifting (and appropriate allocation) of resources between specific activities (and phases/stages) of a project. This requires some trade-off between the execution times and costs of each activity [21]. That is, it is possible to reduce the time for a given task by allocating more resources to its execution; this depletion of resources is later compensated at the expense of the execution times of some non-critical tasks.