“…In particular, studies conducted by consulting firms and by other practitioners have been criticised for lack of academic rigour (Hackman and Wageman, 1995) because of vested interests in the results of the studies (Powel, 1995) and because of the insufficient information provided on research methodology (Sousa and Voss, 2002). The quality of these studies might also have been affected by a lack of theoretical grounding (Flynn et al, 1994;Powell, 1995); a lack of objective statistical evidence Singhal, 1997, 2001); a lack of testing for the reliability and validity of the measurement instruments (Flynn et al, 1994;Raghunathan et al, 1997); and a lack of control for factors that might have produced the observed performance differences (size of firms, industry, nationality, and adoption of TQM vs. non adoption) (Powell, 1995;Hendricks and Singhal, 1997).…”