line style scale issues

im working on a project which has utilities lines along the corridor and have another engineering working on these CADD files. we are using the same workset and workspace but fr some reason our scales are off. when i place the same line type they are coming in 1/10 the size shown. i been using 1"=50' with line scale factor 0.05 while my cowork has the same scale but with a factor or 0.5. this same issue occurs when she opens one of my files where the scale is too small or when i open one from her which turn too big. 

has anyone seen this issue before or know what im talking about