Optimization of Zero Count Parameter Settings to Improve Equipment Reliability and Reduce Maintenance Costs

Abstract

The purpose of this research was to optimize the zero-count verification methodology used in non-viable particle counting equipment for pharmaceutical environmental monitoring. The existing practice required a single-sample zero count with an absolute zero acceptance criterion performed before every sampling point, leading to excessive failures, unnecessary equipment downtime, and increased maintenance costs without improving performance. Historical zero count failure data and maintenance records were analyzed to assess the impact of this approach. Manufacturer calibration guidelines, which define zero count verification as a 10-sample run with acceptance based on the last six samples meeting zero count criteria, served as the technical basis for revising both acceptance criteria and testing frequency. The revised methodology implemented one zero count per sampling session, with additional tests conducted only under predefined trigger conditions. Results showed a substantial reduction in failures, improved equipment availability, and decreased maintenance interventions, demonstrating greater reliability and operational efficiency. Keywords ⎯ Environmental monitoring, manufacturer calibration guidelines, particle counting equipment, zero count verification.