A Boolean function is considered partially defined if its output is unspecified for some combinations of inputs. The papers presented during the latest TFC/TRAI conferences reported previous research on using partially defined logical operators in TRIZ. Uncertainty regarding the requirements may be perceived as an opportunity for expanding the solution space due to relaxed project constraints, paving the way to more innovative outcomes. On the contrary, the uncertainty about the relations between contributing causes makes cause-effect analysis more challenging. While removing all input causes guarantees eliminating the unwanted effect, it may not be necessary in some cases. Previous papers proposed analyzing partially defined operators to identify a minimal set of fully defined candidate functions and selecting the sequence of elimination of the input causes with the lowest total cost estimate. The research objective of this paper is to expand the devised method by using the properties of positive (monotone) Boolean functions and estimating the profitability of calibrating the function by revealing the operator response for specific combinations of inputs. The resulting approach supports systematic handling of partially defined operators by decreasing the uncertainty about the actual logical expression and indicating the contributing causes to be eliminated cost-effectively.