METHOD is a means or manner of procedure,especially a regular and systematic way of accomplishing something.
METHODOLOGY is a set or system of methods , principles and rules for regulating a given discipline, as in the arts or sciences. The purpose of having a methodology is to ensure that others who follow the set of methods will come to the same outcome.
(references from: A Manual for Foundation of Islamic Economics, Basic Principles & Illustrations by Dr. Mohd Nahar Mohd Arshad. )