Enterprise resource planning system is a complex and integrated system which management regards as a strategic tool to make improvement. Owing to its predefined processes and integrated nature, organizations are usually required to make some changes to adopt the system. The perception of high failure rate in ERP implementation motivates researchers to study critical success factors which are expected to help organization implement ERP systems successfully. Although critical success factors in ERP implementation have been quite well studied, it is still one of the popular topics in the field.

This study combined the process and variance approaches to define critical success factors. Based on the ASAP implementation methodology, a critical events chain was formulated. Some critical success factors which identified in prior research were critical events in the chain. Based on the process approach, those events should not be regarded as critical success factors because they were necessary but not sufficient conditions. At the end of the literature review, six potential critical success factors were identified including the surrogates of the critical events chain and the training processes.

A survey was conducted to collect data in a research site which had the systems go-live a few months ago. The six factors were confirmed by factor analysis but one of them was found insignificant in the regression analysis. The five critical success factors include top management support, effective project management, consultants support, perceived usefulness and self-efficacy.

The results of the study indicate that some critical success factors identified in prior research should not be critical success factors. There are critical events chains in ERP implementation and their outcomes should be regarded as critical success factors.