FARIZI, S. A.; PUTRA, B. I. Analysis of Visitor Services Time at the Cooperative and Micro Business Office of Sidoarjo Regency Using the Six Sigma Method Approach to Optimize Micro Business Upgrading : Analisis Waktu Pelayanan Pengunjung di Dinas Koperasi dan Usaha Mikro Kabupaten Sidoarjo Menggunakan Pendekatan Metode Six Sigma Untuk Optimasi Usaha Mikro Naik Kelas. Indonesian Journal of Innovation Studies, [S. l.], v. 27, n. 2, p. 10.21070/ijins.v27i2.2418, 2026. DOI: 10.21070/ijins.v27i2.2418. Disponível em: https://ijins.umsida.ac.id/index.php/ijins/article/view/2418. Acesso em: 13 oct. 2026.