Calculating developer time during development process

Aspects of the invention include computer-implemented methods, computing systems and computer program products for calculating an active time on a software application with respect to a first work item. A computer-implemented method includes retrieving activity data from a software development application and a plurality of input signals generated by a peripheral device. The method further includes determining a causal relationship between the input data and any events described by the activity data. In response to a determination of a causal relationship, a first time interval is calculated between an initial signal and a final signal of the plurality of input signals. The first time interval is compared to an estimated time interval. A schedule of a second work item is determined based on the comparison, wherein the first time interval relates to a first work item.