Six Sigma is a systematic, data-driven methodology for improving processes by reducing waste and defects or errors. The key measure within Six Sigma is the defect. Defects are caused by variation. Six Sigma metrics ( measurements) to tally defects include the defect rate, sigma level, process efficiency and process capability.
The Histology process presents some unique challenges to reducing defects since it remains a time intensive, mostly manual process, with a persistant prevelance of batch processing and lack of industry-wide standards. The large amount of manual handling creates process variations, and also a propensity for human errors such as mis-labeling of cassettes and slides.
Many experts feel that the time has come for industry-wide standards to be applied to histology practice. Six Sigma offers many tools to help the histology laboratory standardize, increase efficiency, and reduce errors. Some specific Six Sigma tools which can help histology laboratories identify error prone steps and process ineffieciencies include Root cause analysis (RCA), Failure mode effect analysis (FMEA), and use of standardization of operating procedures (SOP''s) , which will all help histology laboratories to reduce variation and errors.