This working paper presents a method that supports the development of E-Commerce systems that are in line with a company’s long term strategy. The method, E-MEMO, is being developed within the project ECOMOD that is funded by the German National Research Foundation (DFG). The method includes two major steps. Firstly, it guides the stepwise derivation of a business strategy for E-Commerce from a given set of generic strategies. For this purpose, it takes into account general approaches to support strategic design as well as the peculiarities of strategies for E-Commerce. Secondly, it supports the refinement of a strategy down to the operational level, namely to a set of business processes and the resources that are required by these processes. This is done by selecting appropriate business processes based on certain features of the strategy.