In the past, proficiency testing (PT) items and participation frequency were formulated by accreditation bodies, regardless of the scale, customer type, and economic conditions of a laboratory. In 2010, ILAC P9 began requiring the applicant laboratories considering needs and risk level to make their own PT participation plan (hereafter referred as the PT plan, for short), as long as the PT program was feasible both logistically and economically. The accreditation organization should not only define the minimum requirements for PT participation, but also review whether the PT plan of the laboratory is consistent with the scope of accreditation and provide the necessary guidance. In response to the requirements of ILAC P9, Taiwan Accreditation Foundation (TAF) revised the accreditation criteria document, Requirements for PT Activities (TAF-CNLA-R05). Submitting a PT plan prepared by the laboratory seeking accreditation is required in this revised document. To facilitate applicants learning how to make a plan and implement thereafter, a document—Guidelines for Establishing Plans of Participation in PT Programs (TAF-CNLA-G29)—was developed by TAF based on the concept of risk evaluation.

This article will take one particular case study from TAF-CNLA-G29 to illustrate how to put the risk assessment concepts into the consideration points, formulation procedure, and subsequent review and amendment procedures of the PT plan.