A method for analyzing load run test results of a computer system includes providing a plurality of performance measure sets derived from a first series of load run tests performed over a same time period. Each set comprises a plurality of records and each record has a timestamp and a value. Performance measure records are sorted by value in ascending order, for each performance measure set. Plateau regions are identified in the sorted performance measure sets, for each performance measure. Performance measure records are sorted within each plateau region by time stamp in ascending order, for each performance measure. Overlapping time intervals covered by the plateau regions are identified for the plurality of performance measure sets, and averages of performance measures are computed over the overlapping time intervals.