A system and method are disclosed for predictive determination of a process variable (P) in a technical installation. Measured values for the process variable (P) are recorded at predeterminable points in time. Temporally successive recorded measured values are combined to form a weighted measured value. A discrete measured value is assigned to each weighted measured value. Each weighted measured value that lies in a predeterminable tolerance band is assigned a same discrete measured value. A future temporal progression of the process variable (P) is estimated using a linear regression of the discrete measured values, and a point in time in which the process variable (P) reaches a predeterminable limit value is calculated.