Application of Lean Office and Process Engineering to Improve the Productivity of a Labor Skills Certificate Management System: A Case Study of a National Labor Skills Testing Center

Abstract

This study aims to improve the labor skills certificate management process in a case–study testing center by integrating Lean Office, process engineering, and an AI–Assisted Workflow with Google Workspace. A before–and–after case study was conducted using value stream mapping and ECRS. Time measurements were collected from the same set of 30 certificates, whereas data–error checks covered 95 certificates before improvement and 30 certificates after improvement. The main indicators were lead time, process cycle efficiency, retrieval time, and error rate. The original 6–step process required 4.00 ± 0.30 min/certificate and yielded a PCE of 37.5%. The improved 5–step process used Google Apps Script to create hyperlinks to PDF files stored in Google Drive, with staff verification retained. Lead time decreased to 1.60 ± 0.06 min/certificate (t = 43.9, p < 0.001), retrieval time decreased from 22.5 ± 4.5 min to 0.4 ± 0.1 min (t = 26.9, p < 0.001), and PCE increased to 95.6%. No data error was observed in the post–improvement sample; however, Fisher’s Exact Test yielded p = 0.062, so the error–rate result is interpreted as a decreasing tendency rather than statistical significance at the 0.05 level. The economic analysis indicated an annual time–cost saving of approximately 7,981 THB and a payback period of about four months. The findings suggest that a low–cost digital workflow can reduce retrieval time and redundant clerical work in certificate–based document management.