The resolution process of PPI scandal was led and driven by the UK’s FCA- financial regulator based on powers stipulated in Financial Services and Markets Act 2000. FCA made rules requiring financial institutions concerned to assess mis-selling claims of PPI holders and pay redress to them if mis-selling was found. The opt-out class action, in contrast, is not likely to handle finance mis-selling collectively because commonality requirement is not easily satisfied. The PPI resolution process overcame this problem by assigning the investigation and assessment of individual aspects of the disputes to the financial institutions concerned. This approach is equitable in that financial institutions which are liable to the scandal bears the time and pecuniary cost instead of relying on public resources of courts as in the litigation. The regulator-led resolution can be helpful in designing collective resolution system of finance mis-selling which is characterized as mass victims with small damages.

The research develops the calculation steps of Z sigma level, process capability index(PCI) and process performance index(PPI) applicable to the discrete process in the service industry. The paper presents three following topics used related process indexes according to the precision and accuray in the continuous process. The contents include diverse process indexs for nonconformities by SPC attribute control charts and bias coefficient. The same technique of the nonconformites is also used in the nonconforming units. The practical examples are provided to help easier understanding for users.