I was asked to evaluate how the output changes in response to input variables. For this I have randomly create sensible value of input variables. These are then imported into a software which yields the output variables, however I do not know which formula is used for the calculations. How can I make statements about the sensitivity? Is that possible at all? What are my alternatives?
I am working on evaluating the cost/benefit ratio of some safety measure against natural hazards. Hereby I use different input values depending on which objects (house, bridge, field, etc.) have been affected by which natural hazard (Water, snow, rock, etc).
I have simulated input value ranges for a a certain object being hit by a certain process - ex. family house hit by avalanche. Then I import these into the software (not important which) and it yield the output values by using complex algorithm. The output values is the cost/benefit ratio. The (not important which) software offers a standard cost/benefit ratio calculated using standard input values. I then calculate the difference between the standard cost/benefit ratio with generated one by me. The output look like:
The mean median value in this case is 0.0. But say it was negative, can I say that the standard value generally overestimates the cost/benefit ratio?
More importantly: What can I say about sensitivity from this? I would like to evaluate if some processes and object types are more sensitive to changes in input values than other - is looking at the variabilty of the differences enough?
Until now I only have graphs in my analysis, I would like to get some numbers, statistical test, what can I use?
Additionaly, there is a treshold value for the cost/benefit ratio which indicates the economic efficiency for a certain project(=construction of the safety measure). How can I identify the amount of accepted variability in the input values before the project goes from economically efficient to inefficient ( or vice versa)? Would it be sensible to run a (logistic ?) regression such as cost/benefit ratio ~ Natural hazard + object type + input value?
Very important detail, I use R to do the statistics.