Approach and implementation to access the risk factor associated with complex activities is the purpose of conducting analysis through "p,t" type tests. Complex activities, stiff opposition and inhospitable environment could be associated with increasing the risk factor. A driving simulator model was taken as a four cylinder type car with some more additional equipments fitted into it to simulate a realistic driving environment with a cell-phone as a distracter. The distracter was accomplished by the driving activity while using cell-phone, but the risk that drivers take upon the cell phone was unclear. The performance of drivers proved to be affected badly by a number of distracters that could lead easily to be evolved in crash. Also, the relationship between the difficulty level of a phone conversation and the resulting distraction use to be unclear. The study showed the effect that easy and difficulty cell phone conversations have on driving performance . Participants engaged in a cell phone conversations showed to have higher variations in accelerator pedal position, slower driving with more variations in speed, and a higher level of workload regardless of the difficulty level of the conversation. It is found that the risk factors were 0.86 and 0.79 according to "p" and "t" tests (tables 3 and 4). Also, results constraints variables of same types of tests " t, p" showed that certain increment from 0.68 to 0.80 suggesting that the additional stress reduced the variables leading to higher performance and increasing those towards higher risk factors.