Effort estimation for ERP projects - a systematic review

Enterprise Resource Planning (ERP) systems are large scale integrated systems covering most of the business processes of an enterprise. ERP projects differ from software projects with customization, modification, integration and data conversion phases. Most of the time effort and time estimations are performed in an ad-hoc fashion in ERP projects and as a result they frequently suffer from time and budget overruns. Although there is no consensus on a methodology to estimate size, effort and cost of ERP projects there are various research studies in the field. The purpose of this paper is to review the literature on effort estimation methods for ERP projects, their validations and limitations. The systematic literature review used online journal indexes between January 2000 and December 2016. Studies focusing on effort estimation for ERP projects were selected. Two reviewers assessed all studies and 41 were shortlisted. In most of the studies, cost factors for ERP projects were investigated and validated. Our findings showed that effort estimation methods have mostly used function points as an input. Validations of these methods were mostly done by using history-based validation approaches.