Quality and productivity play important role in manufacturing technology. The quality of any product influences the extent or degree of satisfaction of the consumers during its usage & so quality becomes a major concern for every manufacturing unit. Today's manufacturing industry needs to produce products within lesser time with no compromise shown on quality; in order to tackle these two contrasting criteria; it is necessary to check the quality level of the product either offline or online. In a manufacturing unit, one of customers most specified requirement is surface roughness which is an indicator of the surface quality. In this present work an offline estimation of surface roughness and its variation with respect to changing cutting parameters in turning of aluminium alloy is carried out. Taguchi DOE and ANOVA are employed for finding out the most suitable cutting parameters for minimizing surface roughness. The percentage contribution of each factor towards decreasing the roughness in aluminium alloy is found out

Keywords: design of experiments, ANOVA, MINITAB