The selection of a transfer pricing method always aims at finding the most appropriate method for a particular case. For this purpose, the selection process should take account of the respective strengths and weaknesses of the OECD recognised methods; the appropriateness of the method considered in view of the nature of the controlled transaction, determined in particular through a functional analysis; the availability of reliable information (in particular on uncontrolled comparables) needed to apply the selected method and/or other methods; and the degree of comparability between controlled and uncontrolled transactions, including the reliability of comparability adjustments that may be needed to eliminate material differences between them. No one method is suitable in every possible situation, nor is it necessary to prove that a particular method is not suitable under the circumstances. See TPG 2.2