what is a parameter diagram (P-diagram) used for? (a) structuring an analysis of potential failure modes to facilitate development of robustness actions that will improve the ability of a design to operate in the presence of unforeseen usages and conditions. (b) determining the optimal ideal parameter values for the performance of a design (c) structuring an analysis of key casual drivers for cost in a design to facilitate identification of cost reduction opportunities (d) determining the priorities users have for functions that a new product being designed could deliver