In the design theory of fiber reinforced mixture, it is assumed that well fiber distribution and orientation are attained in the composite. In practice, non uniform distribution of fibers tends to degrade as well as introduce undesirable variability into the mechanical properties of this material. The fiber distribution mainly depends upon workability properties of mixture as well as the volume fraction and aspect ratio of fibers in the mixture. The objective of this paper is to optimize the mechanical properties of glass fiber reinforced self-consolidating cementitious material (FRSCCM) through workability properties during processing. Based on the obtained results, critical and dense fiber factors have defined to show the variability of workability and mechanical properties of suspension including glass fibers. For fiber factor between critical and dense fiber factor, significant improvement in hardened properties was gained and the mixture was still workable enough to flow under its own weight and no signs of instability and fiber balling were observed. On the other hand, for mixture with fiber factor above the dense fiber factor, non uniform distribution and clumping of fibers occurred, leading to a poor mechanical behavior of mixtures. According to the obtained results, the critical and dense fiber factors were 30 and 450, respectively. In addition, for fiber factor lower than 30 the system could be considered as dilute suspension and fibers were far apart from one another and so the effect of fibers on mechanical properties was negligible.