A computer-implemented method and program product for estimating cost and/or time requirements for migrating an application from one platform to another. The method includes receiving identifications for tasks, receiving at least one assessment type selected for estimating cost and/or time requirement for migration, where the assessment type delineates a degree of accuracy for estimating the cost and/or time requirement for migration, correlating base costs and/or time requirements to the tasks identified, receiving identifications of attributes that affect base costs and/or time requirements, correlating cost and/or time factors to the tasks, a respective cost factor and/or time factor indicating an amount by which an attribute affects the respective base cost and/or time requirement for a task, and estimating cost and/or time requirements for each task, by applying the respective cost and/or time factors for each task to the respective base cost and/or base time requirements for each task.