Mathematical models of gene editing using CRISPR
There are several probabilities that you need to take into account. 


The efficiency of DNA transformation of CRISPR encoding DNA and
target DNA into the host cell (varies between cell types and
transformation agent).
Efficiency of cutting by CRISPR at target site. (varies by DNA compaction - which varies by site and cell type, and guide RNA) 
Number and cutting efficiency at off targeting sites. 
Efficiency of degradation of free DNA by cellular antiviral systems
(varies between cell types)
Efficiency of DNA repair machinery to fix dsDNA breaks. (thus removing CRISPR cut sites. Varies by cell type)
Efficiency of recombination machinery (homologous
recombination and microhomologous recombination) (which is used to
insert new DNA sequence).  
Probability of NHEJ damaging target site. (which can delete the CRISPR cut site)


Too many things to count. 

However to give you some idea. The efficiency of CRISPR making a correctly targeted knock in for DT40 (chicken lymphoma) is  ~1% of all resistant colonies (ie colonies that have taken up the DNA seq used to make the knock in), when lipofectamine reagents are use. Lipofectamin trasfromation efficiency varies depending on the size of the transformed DNA, host cell type and plating density. So for a 5kb construct that transformation efficiency varies between 30%-50%. 

CRISPR is nearly 100% efficient in yeast cells, ie all knock in cells are correctly targeted. This is likely due to the high levels of HR in yeast