Scenario 5: Mechanical-Electro (ME) Audit Stages
Mechanical-Electro, better known as ME, is an American company that provides mechanical and electrical services in China. Their services range from air-conditioning systems, ventilation systems, plumbing, to installation of electrical equipment in automobile plants, electronic manufacturing facilities, and food processing plants.
Due to the fierce competition from local Chinese companies and failing to meet customer requirements, ME ' s revenue dropped significantly. In addition, customers ' trust and confidence in the company decreased, and the reputation of the company was damaged.
In light of these developments, the top management of ME decided to implement a quality management system (QMS) based on ISO 9001. After having an effective QMS in place for over a year, they applied for a certification audit.
A team of four auditors was appointed for the audit, including Li Na as the audit team leader. Initially, the audit team conducted a general review of ME ' s documents, including the quality policy, operational procedures, inventory lists, QMS scope, process documentation, training records, and previous audit reports.
Li Na stated that this would allow the team to maintain a systematic and structured approach to gathering documents for all audit stages. While reviewing the documented information, the team observed some minor issues but did not identify any major nonconformities. Therefore, Li Na claimed that it was not necessary to prepare a report or conduct a meeting with ME ' s representatives at that stage of the audit. She stated that all areas of concern would be discussed in the next phase of the audit.
Following the on-site activities and the opening meeting with ME ' s top management, the audit team structured an audit test plan to verify whether ME's QMS conformed to Clause 8.2.1 (Customer Communication) of ISO 9001.
To do so, they gathered information through group interviews and sampling. Li Na conducted interviews with departmental managers in the first group and then with top management. In addition, she chose a sampling method that sufficiently represented customer complaints from both areas of ME ' s operations.
The team members were responsible for the sampling procedure. They selected a sample size of 4 out of 45 customer complaints received weekly for electrical services and 2 out of 10 complaints for mechanical services.
Afterward, the audit team evaluated the evidence against the audit criteria and generated the audit findings.
Li Na chose a sampling method that sufficiently represents customer complaints from both areas of ME's operations. Which sampling method fits that description?