Estimating the Cost of Developing Customizations to Packaged Application Software Using Service Oriented Architecture

Abstract

Service-oriented way of building customizations to packaged applications is an emerging alternative to the traditional way of modifying the package application directly to implement customizations. Estimating the effort at an early stage (before detailed design) in the services engagement is important to reduce the perceived risk of the new approach and to demonstrate the potential cost efficiencies. In this paper we present a method to estimate the effort and cost involved in developing customizations to packaged application software (such as SAP and Oracle ERP software) using service-oriented architecture/design (SOA) style. Taking only a description of business processes to be customized, we estimate the effort and costs of implementing those customizations. We use novel artifact-centric and linguistic analysis approaches to estimate the business object count which lies at the center of our cost estimation model. The model is currently being piloted at a large IT services organization involved in implementing packaged application software for clients. Initial experiments reveal that the cost and effort estimates are within 10% range of the benchmark estimates developed after requirements gathering and detailed design.