In LCA, practitioner may reach different results depending on the scope of the study, system boundaries and allocation procedures being taken in LCI and choice of characterization factors in LCIA. The influence of these procedures on the result has to be discussed in the phase of "interpretation". In many cases of current LCI, results of emissions and resource consumption are expressed by a single numerical value. However, each process data is suffering from measurement error and estimation error. In the ISO standard, it is necessary to evaluate data quality using the techniques to determine the effect of data error such as “sensitivity check" and "uncertainty analysis", when the practitioner undertakes interpretation.

Further information

SETAC ’’Guidelines for Life-Cycle Assessment A code of Practice”, 1993 SETAC “Towards a Methodology for Life Cycle Impact Assessment”,1996