Case studies: Six Sigma in practice
If the cap fits, wear it. Charles Dickens
It is well accepted that in the 1970s Japanese firms set the pace by their focus on quality and performance reviews. By comparison western companies (i.e. USA and European owned and operated companies) appeared to be less concerned about the importance of quality measures and the impact of standards of performance on bottom-line results. TQM initiatives that were taken seemed to concentrate on softer cultural issues rather than ‘hard’ performance standards. However, with the introduction of Six Sigma tools in the 1980s Motorola revolutionized the quality movement. Western companies that operated at levels of two to three sigma (with between 45 500 and 2700 defects per million operations) became increasingly interested in improving their performance standards (and their share price). Although 99 per cent sounds very good, it slowly dawned on companies that there is a tremendous difference between 99 per cent and 99.9997 per cent – for example, for every million articles of mail the difference is between 10 000 lost items and 3 lost items. Again, for 2 million prescriptions of medicine per annum 99 per cent = 20 000 wrong prescriptions, whereas 99.9997 per cent in theory equates to 7 wrong prescriptions (and for 20 million prescriptions the decrease is from 200 000 errors to 68). In practice 99.9997 per cent would mean no wrong prescriptions, as the process and culture is conditioned for zero defects rather than being one that accepts that it is inevitable, and acceptable, that mistakes will occur.