Abstract: Size of an enterprise application integration project can be determined by based on data exchange activities, data processing activities, other systemic requirements for the integration and associated weights. Data exchanges and processing activities can be categorized as reception, validation, transformation, publishing, enrichment, or other activities. Activities can be further divided into sub-activities based on complexity of integration tasks. A total project build size can be obtained based on numbers of sub-activities and associated weights. Typically, weights are software vendor dependent, and a total build size is determined as a summation of a product of numbers of sub-activities and associated vendor specific weights.