In this article, a matrix model (ones (rank organization of types of work matrix (ROTW)) is used to determine the location and connection in space and time of the main and additional parallel grippers. The main works are used to calculate the values of grippers by a sequential parallel method for technologically similar processes, and additional ones - by a parallel method to increase the amount of resource. The mathematical model includes the research objective and parameters that affect the construction time. The optimal solution is achieved by the parallel method in stages: by reducing the periods and duration of flow-lines, initial and final values of grips and critical works. There has been no study of a sequential method of reducing the construction period using only existing crews. The effectiveness of the phased method of reducing the construction period is determined in comparison with the method of using additional parallel flow-lines