Enterprise Resource Planning (ERP) packages are information systems that automate the business processes of organizations thereby improving their operational efficiency substantially. ERP projects that involve customization are often affected by inaccurate estimation of efforts. Size of the software forms the basis for effort estimation. Methods used for effort estimation either employ function points (FP) or lines of code (LOC) to measure the size of customized ERP packages. Literature review reveals that the existing software size methods which are meant for custom-built software products may not be suitable for COTS products such as customized ERP packages. Hence, the effort estimation using conventional methods for customized ERP packages may not be accurate. This paper proposes a new approach to estimate the size of customized ERP packages using Package Points (PP). The proposed approach was validated with data collected from 14 ERP projects delivered by the same company. A positive correlation was observed between Package Points (PP) and the efforts of these projects. This result indicates the feasibility of our proposed approach as well as the positive climate for its utility by the project managers of future ERP projects. Lastly, we examine the implication of these results for practice and future research scope. 
An approach to estimate the size of ERP package using package points