**2.1. Data collection**

Manufacturing processes analysed were metal bending and Laser-cutting. In both cases, no other process- or operation-related resources, apart from electricity, were consumed, but the influence of the hydraulic oil needs during the equipment's lifetime was considered in the LCA analysis of a conventional press-brake used for bending. In the case of the Laser cutting machine, with individualised sub-systems, power consumption measurements were followed in parallel for the 3 main sub-systems, namely the Laser source, the chiller and the control unit (Oliveira et al, 2010).

The energy consumption data were acquired with a Janitza Power Analyzer, model UMG 604, a measuring system able to measure and calculate multiple electrical variables on 3-phase AC systems. The system was configured to record current, voltage, and power factor per line every 1 s, installed in the machine-tool's electrical cabinet; accounts over 24 h for each test have been followed. In the used configuration, the system is capable to measure low-voltage systems up to 300 V conductor to earth and currents up to 60 A, with maximum measuring uncertainties of ±0.50 V and ±0.15 A, respectively, over long periods of time (Santos et al, 2011).

The yearly consumption of hydraulic oil was taken from the Preventive Maintenance Plan provided by the machine-tools local manufacturer involved in the time-studies (Adira S.A., 2010).
