An engineering change (EC) refers to a modification of products and components including purchased parts or even supplies after product design is finished and released to the market. While any company involved in product development would have to deal with engineering changes, the area of engineering change management hasn't received much attention from the research community. It is partly because of its complexity and lack of appropriate research tools. In this paper, we present preliminary research results of modeling the engineering change management (ECM) process using an agent-based modeling and simulation technique. The aim of the research reported in this paper is to study optimal strategies of resource allocation for a company when it is dealing with two kinds of ECs: "necessary ECs" and "initialized ECs." We discuss results from these simulation models to illustrate some insights of ECM, and present several research directions from these results.