The main idea of this article is the necessity to take into account the multi-variant technological and organizational solutions of individual construction works in order to ensure rational planning for the implementation of construction projects. In practice, selection of construction works most often limited to the evaluation of technological and organizational solutions on the basis of time and cost criteria. However, it should be remembered that construction projects usually have a complex technological and organizational structure. This fact may increase the durations and costs of individual works in relation to their planned durations and costs. Therefore, the authors propose to take into account the criterion of technological and organizational complexity of the assessed construction work. The article describes the procedure for the technological and organizational optimization of construction works. A numerical example of the method of selecting technological and organizational solutions with the use of a fuzzy relation of preferences is also presented. The article also proposes to combine the computational selection model with the network planning model in a graphic form. This approach expands the computational and decision-making possibilities of network models in the practice of planning construction projects.

The new approach to the construction project planning is presented in the article. The classical net model is enriched by the fuzzy decision node. The decision node allows for alternate choices dependent on appearing circumstances. The alternative net model with fuzzy decision node is an acyclic multi-graph, where some, chosen nodes (events) have multiple connections. These connections represent alternative methods of the certain work execution. Every work (activity) (i, j) in the net model with alternative methods of work execution, despite the basic information comprising the execution time, the cost, the number of necessary workers, should comprise additional information e.g. about a complexity of works, a real feasibility. The alternative ways of a given work execution are evaluated in the decision node based on the fuzzy decision model. Each method is evaluated by assigning it the preference level in a form of the value of the membership function – „equal or higher” μ_≥. The most preferable way of the work execution in a given circumstances, will have the highest value of preference level. When the choice is done the net model is solved in the traditional way. Therefore, the paper concentrates on the process of choosing the method of work execution in the fuzzy decision node. The example calculations accompanying the process of decision taking are presented too. The model requires the use of linguistic variables, a fuzzy numbers, as well as fuzzy preference relations together with some calculations applied the probability theory.