An empirical analysis of the integration of internal and external management system audits

•The paper investigates the integrations of MSs audits.•It also compares internal and external management system audits.•The integration level found is very high for all the audit elements analyzed.

This paper presents the results of a research study whose main objectives were to analyze and compare internal and external management system audits regarding their implementation and integration in Spanish companies. Nine variables were investigated, namely the audit team, schedule, strategy, plan, report, methodology, guidelines, frequency and outputs. The results show that there are some significant differences regarding the audit team formation, the auditing guidelines used and the frequency of conducting the audits. The rest of the variables did not exhibit significant differences between internal and external audits. In addition, the integration level of both these categories of audits is very high for all the audit elements analyzed.